Level Up:
1st Level: Comprehend Languages, Detect Magic, Find Familiar, Fog Cloud, Mage Armor, Magic Missile, Sleep, Shield
2nd Level: Enlarge/Reduce, Levitate, Misty Step, Web
3rd Level: Fireball, Fly, Hypnotic Pattern, Leomund's Tiny Hut
4th Level: Arcane, Eye, Dimension Door, Otiluke's Resilient Sphere, Polymorph
5th Level: Bigby's Hand, Telekinesis, Teleportation Circle, Wall of Force
6th Level: Contingency, Disintegrate, Elminster's Effulgent Spheres, Scatter
7th Level: Crown of Stars, Mordenkainen's Magnificent Mansion, Reverse Gravity, Simulacrum
8th Level: Demiplane, Holy Star of Mystra, Maze, Power Word: Stun
9th Level: Foresight, Meteor Swarm, Shapechange, True Polymorph

Spell Breaker: Counterspell, Dispel Magic
Abjuration Savant: Absorb Elements, Arcane Lock, Magic Circle, Banishment, Circle of Power, Guards and Wards, Symbol, Antimagic Field, Prismatic Wall

Copying Spells into the Spellbook:
1st Level: Alarm, Feather Fall, Identify, Illusory Script, Longstrider, Protection from Evil and Good, Tasha's Hideous Laughter, Tenser's Floating Disk, Unseen Servant, Thunderwave [10]
2nd Level: Augury, Blindness/Deafness, Darkvision, Enhance Ability, Gentle Repose, Hold Person, Invisibility, Knock, Magic Mouth, Mirror Image, Nystul's Magic Aura, Rime's Binding Ice, Rope Trick, See Invisibility, Skywright, Tasha's Mind Whip [16]
3rd Level: Cacophonic Shield, Catnap, Clairvoyance, Glyph of Warding, Haste, Intellect Fortress, Lightning Bolt, Major Image, Phantom Steed, Remove Curse, Sending, Sleet Storm, Slow, Speak with Dead, Tiny Servant, Tongues, Water Breathing [17]
4th Level: Divination, Evard's Black Tentacles, Fire Shield, Galder's Speedy Courier, Gate Seal, Greater Invisibility, Hallucinatory Terrain, Ice Storm, Leomund's Secret Chest, Mordenkainen's Private Sanctum, Raulothim's Psychic Lance, Stoneskin, Summon Greater Demon, Spellfire Storm, Watery Sphere [15]
5th Level: Animate Objects, Bigby's Hand, Cone of Cold, Conjure Elemental, Far Step, Hold Monster, Legend Lore, Modify Memory, Passwall, Planar Binding, Rary's Telepathic Bond, Steel Wind Strike, Songal's Elemental Suffusion [13]
6th Level: Arcane Gate, Chain Lightning, Globe of Invulnerability, Programmed Illusion, True Seeing [5]
7th Level: Forcecage, Plane Shift, Sequester, Teleport [4]
8th Level: Mind Blank [1]
9th Level: Blade of Desaster, Gate, Time Stop, Wish [4]
Total: (10x50)+(16x200)+(17x300)+(15x2000)+(13x3000) = 77.800 gp
Scrolls purchased for Levels 1-5; Copy spells from books/scrolls for Levels 6-9.
Downtime: 99
Copying Spells into the Book: (10x1x50)+(16x2x50)+(17x3x50)+(15x4x50)+(13x5x50)+(5x6x50)+(4x7x50)+(1x8x50)+(4x9x50) = 160.000 gp

Components & Miscellaneous:
1x An exquisite chest, 3 feet by 2 feet by 2 feet, constructed from rare materials worth at least 5.000 gp, and a Tiny replica made from the same materials worth at least 50 gp (Leomund's Secret Chest component)
1x A statuette of yourself carved from ivory and decorated with gems worth at least 1.500 gp (Contingency)
1x A jade circlet worth 1,500+ GP (Shapechange)
1x A miniature portal carved from ivory, a small piece of polished marble, and a tiny silver spoon; worth in total 15 gp (Mordenkainen's Magnificent Mansion)
3x Powdered ruby worth 4.500 gp (Simulacrum)
25x Plane Shift Forked Metal Rods (25x 250gp = 6250gp) [Material Plane, Feywild, Shadowfell, Astral Plane, Ethereal Plane, Elemental Plane of Fire/Earth/Water/Air, Limbo, Mechanus, Acheron, Nine Hells, Gehenna, Hades, Carceri, Abyss, Pandemonium, Arcadia, Mount Celestia, Bytopia, Elysium, Beastlands, Aborea, Ysgard]

Spellcasting:
Contingency
Level 6 - Abjuration
Casting Time: 10 minutes
Range: Self
Components: V, S, M (a gem-incrusted statuette of yourself worth 1,500+ GP)
Duration: 10 days
Choose a spell of level 5 or lower that you can cast, that has a casting time of an action, and that can target you. You cast that spell—called the contingent spell—as part of casting Contingency, expending spell slots for both, but the contingent spell doesn't come into effect. Instead, it takes effect when a certain trigger occurs. You describe that trigger when you cast the two spells. For example, a Contingency cast with Water Breathing might stipulate that Water Breathing comes into effect when you are engulfed in water or a similar liquid.
The contingent spell takes effect immediately after the trigger occurs for the first time, whether or not you want it to, and then Contingency ends.
The contingent spell takes effect only on you, even if it can normally target others. You can use only one Contingency spell at a time. If you cast this spell again, the effect of another Contingency spell on you ends. Also, Contingency ends on you if its material component is ever not on your person.
...
Trigger: If I am targeted by a spell or an effect, that would reduce me to 0 hit-points or instantly kill or destory me
Effect: Cast Otiluke's Resilient Sphere
...
Otiluke's Resilient Sphere
Level 4 - Evocation
Casting Time: Action
Range: 30 feet
Components: V, S, M (a glass sphere)
Duration: Concentration, up to 1 minute
A shimmering sphere encloses a Large or smaller creature or object within range. An unwilling creature must succeed on a Dexterity saving throw or be enclosed for the duration.
Nothing-not physical objects, energy, or other spell effects can pass through the barrier, in or out, though a creature in the sphere can breathe there. The sphere is immune to all damage, and a creature or object inside can't be damaged by attacks or effects originating from outside, nor can a creature inside the sphere damage anything outside it.
The sphere is weightless and just large enough to contain the creature or object inside. An enclosed creature can take an action to push against the sphere's walls and thus roll the sphere at up to half the creature's Speed. Similarly, the globe can be picked up and moved by other creatures.
A Disintegrate spell targeting the globe destroys it without harming anything inside.

Level Up:
1st Level: Comprehend Languages, Detect Magic, Find Familiar, Fog Cloud, Mage Armor, Magic Missile, Sleep, Shield
2nd Level: Enlarge/Reduce, Levitate, Misty Step, Web
3rd Level: Fireball, Fly, Hypnotic Pattern, Leomund's Tiny Hut
4th Level: Arcane, Eye, Dimension Door, Otiluke's Resilient Sphere, Polymorph
5th Level: Bigby's Hand, Telekinesis, Teleportation Circle, Wall of Force
6th Level: Contingency, Disintegrate, Elminster's Effulgent Spheres, Scatter
7th Level: Crown of Stars, Mordenkainen's Magnificent Mansion, Reverse Gravity, Simulacrum
8th Level: Demiplane, Holy Star of Mystra, Maze, Power Word: Stun
9th Level: Foresight, Meteor Swarm, Shapechange, True Polymorph

Spell Breaker: Counterspell, Dispel Magic
Abjuration Savant: Absorb Elements, Arcane Lock, Magic Circle, Banishment, Circle of Power, Guards and Wards, Symbol, Antimagic Field, Prismatic Wall

Copying Spells into the Spellbook:
1st Level: Alarm, Feather Fall, Identify, Illusory Script, Longstrider, Protection from Evil and Good, Tasha's Hideous Laughter, Tenser's Floating Disk, Unseen Servant, Thunderwave [10]
2nd Level: Augury, Blindness/Deafness, Darkvision, Enhance Ability, Gentle Repose, Hold Person, Invisibility, Knock, Magic Mouth, Mirror Image, Nystul's Magic Aura, Rime's Binding Ice, Rope Trick, See Invisibility, Skywright, Tasha's Mind Whip [16]
3rd Level: Cacophonic Shield, Catnap, Clairvoyance, Glyph of Warding, Haste, Intellect Fortress, Lightning Bolt, Major Image, Phantom Steed, Remove Curse, Sending, Sleet Storm, Slow, Speak with Dead, Tiny Servant, Tongues, Water Breathing [17]
4th Level: Divination, Evard's Black Tentacles, Fire Shield, Galder's Speedy Courier, Gate Seal, Greater Invisibility, Hallucinatory Terrain, Ice Storm, Leomund's Secret Chest, Mordenkainen's Private Sanctum, Raulothim's Psychic Lance, Stoneskin, Summon Greater Demon, Spellfire Storm, Watery Sphere [15]
5th Level: Animate Objects, Bigby's Hand, Cone of Cold, Conjure Elemental, Far Step, Hold Monster, Legend Lore, Modify Memory, Passwall, Planar Binding, Rary's Telepathic Bond, Steel Wind Strike, Songal's Elemental Suffusion [13]
6th Level: Arcane Gate, Chain Lightning, Globe of Invulnerability, Programmed Illusion, True Seeing [5]
7th Level: Forcecage, Plane Shift, Sequester, Teleport [4]
8th Level: Mind Blank [1]
9th Level: Blade of Desaster, Gate, Time Stop, Wish [4]
Total: (10x50)+(16x200)+(17x300)+(15x2000)+(13x3000) = 77.800 gp
Scrolls purchased for Levels 1-5; Copy spells from books/scrolls for Levels 6-9.
Downtime: 99
Copying Spells into the Book: (10x1x50)+(16x2x50)+(17x3x50)+(15x4x50)+(13x5x50)+(5x6x50)+(4x7x50)+(1x8x50)+(4x9x50) = 160.000 gp

Components & Miscellaneous:
1x An exquisite chest, 3 feet by 2 feet by 2 feet, constructed from rare materials worth at least 5.000 gp, and a Tiny replica made from the same materials worth at least 50 gp (Leomund's Secret Chest component)
1x A statuette of yourself carved from ivory and decorated with gems worth at least 1.500 gp (Contingency)
1x A jade circlet worth 1,500+ GP (Shapechange)
1x A miniature portal carved from ivory, a small piece of polished marble, and a tiny silver spoon; worth in total 15 gp (Mordenkainen's Magnificent Mansion)
3x Powdered ruby worth 4.500 gp (Simulacrum)
25x Plane Shift Forked Metal Rods (25x 250gp = 6250gp) [Material Plane, Feywild, Shadowfell, Astral Plane, Ethereal Plane, Elemental Plane of Fire/Earth/Water/Air, Limbo, Mechanus, Acheron, Nine Hells, Gehenna, Hades, Carceri, Abyss, Pandemonium, Arcadia, Mount Celestia, Bytopia, Elysium, Beastlands, Aborea, Ysgard]

Spellcasting:
Contingency
Level 6 - Abjuration
Casting Time: 10 minutes
Range: Self
Components: V, S, M (a gem-incrusted statuette of yourself worth 1,500+ GP)
Duration: 10 days
Choose a spell of level 5 or lower that you can cast, that has a casting time of an action, and that can target you. You cast that spell—called the contingent spell—as part of casting Contingency, expending spell slots for both, but the contingent spell doesn't come into effect. Instead, it takes effect when a certain trigger occurs. You describe that trigger when you cast the two spells. For example, a Contingency cast with Water Breathing might stipulate that Water Breathing comes into effect when you are engulfed in water or a similar liquid.
The contingent spell takes effect immediately after the trigger occurs for the first time, whether or not you want it to, and then Contingency ends.
The contingent spell takes effect only on you, even if it can normally target others. You can use only one Contingency spell at a time. If you cast this spell again, the effect of another Contingency spell on you ends. Also, Contingency ends on you if its material component is ever not on your person.
...
Trigger: If I am targeted by a spell or an effect, that would reduce me to 0 hit-points or instantly kill or destory me
Effect: Cast Otiluke's Resilient Sphere
...
Otiluke's Resilient Sphere
Level 4 - Evocation
Casting Time: Action
Range: 30 feet
Components: V, S, M (a glass sphere)
Duration: Concentration, up to 1 minute
A shimmering sphere encloses a Large or smaller creature or object within range. An unwilling creature must succeed on a Dexterity saving throw or be enclosed for the duration.
Nothing-not physical objects, energy, or other spell effects can pass through the barrier, in or out, though a creature in the sphere can breathe there. The sphere is immune to all damage, and a creature or object inside can't be damaged by attacks or effects originating from outside, nor can a creature inside the sphere damage anything outside it.
The sphere is weightless and just large enough to contain the creature or object inside. An enclosed creature can take an action to push against the sphere's walls and thus roll the sphere at up to half the creature's Speed. Similarly, the globe can be picked up and moved by other creatures.
A Disintegrate spell targeting the globe destroys it without harming anything inside.