I've mentioned this in-game, but I thought I'd mention here that there are certain collectibles that are worth more than what you trade them for to the collectors. Deadly Feverblanch mushrooms are going for 500 platinum or more at auction. I've sold a vial of pure water for 1,000 platinum. Look for things that can be used in the Stone of Change rituals, and don't trade them away.
Pure Water- 5 used in Alchemical Armor Edrich Ritual (+1 AC)
Adamantine Ore- 10 used in Adamantine Ritual 1, 15 used in Adamantine Ritual 2, done to increase item's durability.
Soul Gem: Essence of Earth- 10 used in Adamantine Ritual 1, 20 used in Adamantine Ritual 2, done to increase item's durability.
Tomes: Prophecies of Kyber- 2 used in Alchemical Shield Eldritch Ritual, to increase your shield's AC by 1.
Silver Flame Hymnals- 6 used in Alchemical Shield Eldritch Ritual, to increase your shield's AC by 1.
Luminescent Dusts- 3 used in Force Damage Ritual, to add additional 1 point of force damage every hit to your weapon.
Fragrant Drowshood mushrooms- 9 used in Force Damage Ritual, to add 1 point of force damage every hit to your weapon.
Sparkling Dusts- 6 used in the Force Critical Ritiual, to add 1d4 points of force damage on each successful critical hit to your weapon.
Deadly Feverblanch Mushrooms- 12 used in the Force Critical Ritiual, to add 1d4 points of force damage on each successful critical hit to your weapon.
Lightning-Split Soarwoods- 4 used in the Resistance Ritual, which adds +1 competence bonus to saves to your jewelery item.
Funerary Tokens- 22 used in the Resistance Ritual, which adds +1 competence bonus to saves to your jewelery item.
Pure Water- 5 used in Alchemical Armor Edrich Ritual (+1 AC)
Adamantine Ore- 10 used in Adamantine Ritual 1, 15 used in Adamantine Ritual 2, done to increase item's durability.
Soul Gem: Essence of Earth- 10 used in Adamantine Ritual 1, 20 used in Adamantine Ritual 2, done to increase item's durability.
Tomes: Prophecies of Kyber- 2 used in Alchemical Shield Eldritch Ritual, to increase your shield's AC by 1.
Silver Flame Hymnals- 6 used in Alchemical Shield Eldritch Ritual, to increase your shield's AC by 1.
Luminescent Dusts- 3 used in Force Damage Ritual, to add additional 1 point of force damage every hit to your weapon.
Fragrant Drowshood mushrooms- 9 used in Force Damage Ritual, to add 1 point of force damage every hit to your weapon.
Sparkling Dusts- 6 used in the Force Critical Ritiual, to add 1d4 points of force damage on each successful critical hit to your weapon.
Deadly Feverblanch Mushrooms- 12 used in the Force Critical Ritiual, to add 1d4 points of force damage on each successful critical hit to your weapon.
Lightning-Split Soarwoods- 4 used in the Resistance Ritual, which adds +1 competence bonus to saves to your jewelery item.
Funerary Tokens- 22 used in the Resistance Ritual, which adds +1 competence bonus to saves to your jewelery item.