I - Rules
(see FAQ 1.3, p.16)
|Effect:||When you draw 1 or more treasure cards, draw 1 extra treasure card, then choose 1 and return it to the bottom of the deck, facedown.|
Road to Legend
The Appraiser skill can be learned at Dawnsmoor in the Advanced Campaign.
Sea of Blood
The Appraiser skill can be learned at Orris in the Sea of Blood Advanced Campaign.
II - FAQ
How does Appraisal interact with the new market and treasure rules?
When visiting the Market, Appraisal may be used only if the hero visiting the market has the skill. Appraisal may be used on any chest that produces one or more treasures, regardless of whether or not hero with Appraisal is the one who opened the chest.
III - Tactics
Appraiser is a nice subterfuge skill to have in vanilla Descent. It often happens that you specialize in one type of weapon (melee, ranged or magic) but that you end up picking the wrong category from the treasure deck and then need to waste a turn or two to swap items with another hero.
In the Advanced campaign, this skill is still good if you shop often, but it's probably not the first skill you want to buy with your experience points and coins.