The workshop becomes available in Chapter 02. If you get all the materials in the previous Dungeon, you should always have exactly have enough to buy all upgrades when they are unlocked, with the exception of Chapter 9 where you will be 1 Anu short. The achievement seems to only require the combat upgrades, but here is a list of all of them. If you go for the other collection achievements you will be able to buy all of these anyway.
Chapter 02
- Village Improvement - Adds streets and fences to the 'Farm' area. Cost: 1 Green Material
- Ingredient: Seaweed - Adds additional Seaweek racks to the 'Beach' area and allows you to cook with seaweed. Cost: 3 Green Material, 1 Anu
- Essence Extractor - Gain essence when hitting enemies. Cost: 3 Green Material, 2 Anu
Chapter 03
- Revive - Gain 40% heath and temporary invulnerability upon death. Cost: 3 Green Material, 3 Anu
- Flowers & Greens - Adds Flowers to the farm. Cost: 2 Green Material
- Pasture Upgrade - Available after rescuing Cuk - Adds hay to the pasture. Cost: 2 Green Material
Chapter 04
- Spire Extension: Barrier - Gives you a second spire option, with rotating defensive orbs, but it heals for less. Cost: 3 Green Material, 3 Anu
- Pond Restoration - Adds a pond to the farm. Cost: 2 Green Material
- Guardian Statue Repainting - Available after rescuing Jub - Paints all the guardian statues in the town hall. Cost: 2 Green Material
Chapter 05
- Monkey Basecamp - Cleans up the coastal ruins and adds some decorations. Cost: 2 Gold Material
- Essence Container - Increases Essence bar stack. Cost: 3 Gold Material, 2 Anu
- Ingredient: Rice - Available after rescuing Pipit - Adds a rice farm to the coastal ruins. Allows you to cook with rice. Cost: 3 Gold Material, 1 Anu
Chapter 06
- Museum Improvement 1 - Cleans up the 'Gold Pyramid' area and adds museum displays. Cost: 2 Gold Material
- Beast Fury - Available after rescuing Turbo - Deal more damage at low health. Cost: 5 Gold Material, 3 Anu
Chapter 07
- Workshop Improvement - Changes the external appearance of the workshop. Cost: 2 Gold Material
- Kitchen Upgrade - Increase health gained from eating food. Cost: 3 Gold Material, 3 Anu
- Museum Improvement 1 - Adds more decorations to the 'Gold Pyramid' area. Cost: 2 Gold Material
Chapter 08
- Heavy Attack Upgrade - Enemies knocked back with heavy attack also damage other enemies on impact. Cost: 4 Indigo/Red Material, 2 Anu
- Ingredient: MSG - Available after rescuing Sasa - Adds a sugarcan farm to the city. You can now cook with MSG. Yum. Cost: 3 Indigo/Red Material, 1 Anu
Chapter 09
- Spire Extension: Turret - Gives you a new spire option with long range projectiles. Cost: 3 Indigo/Red Material, 2 Anu
- Lab Upgrade - Cleans up and redecorates the lab. Cost: 2 Indigo/Red Material
- Damage Reduction - Available after rescuing Sei - Gives a chance to reduce damage from enemies. Cost: 2 Indigo/Red Material, 2 Anu
Chapter 10
- Trash Reduction - Cleans up the city. Cost: 5 Indigo/Red Material, 1 Anu
- Go Green Movement - Adds some greenery to the city. Cost: 2 Indigo/Red Material, 1 Anu