Selling unidentified loot

[zuljita]

Suppose delvers find a tin of balm of regeneration, but lack any appropriate skills to tell what it is, or a bolt of spider silk, or a fancy book. Suppose they lug the strange unidentified objects back to town anyway. What kind of price can they get? Are there rules for finding a merchant who will tell you what you have before making an offer?

Is the correct solution to require them to go looking for a hireling for a day with the right skills? if yes, does that mean that hiring a bard for a day could wildly improve your final loot? Open to suggestions.