Ok so a while back I sold one of the Falmer eyes to delvin and stole it back. But he will only buy that one eye once. So now I'm stuck with both of them. The eyes are worth 2500 septims each. Is there any NPCs who can buy them for full price?
You can either find a merchant with enough gold to buy them, or one with enough stuff you want to buy to offset the extra value.
You won't be getting the full 2500 gold each, but we'll look for a merchant with that much to ensure that they have enough regardless of your bartering ratio.
You can find a list of merchants and their available gold amount at the Elder Scrolls Wiki.
The only merchants on that list with at least 2500 gold are fences:
Fences start with 1,000 gold, and get more as you do more special jobs for Delvin Mallory. With three cities influenced, they'll have 3,000 gold. They have 4,000 gold once all of these jobs are finished.
Although they don't have the larger value listed on the list I linked, the other fences should have up to 4,000 gold as well. They are:
- Mallus Maccius at the Honningbrew Meadery
- Enthir at the Mages' College
- Khajit Caravans here and there
There's a potentially relevant note on the fences page:
All fences have identical amounts of gold, so increasing one increases them all. Due to this, probably the best fence would have to be Gulum-Ei, as it is possible to go to the Temple of the Divines and get the blessing of Zenithar and (if the Speech skill is less than 100) go and see the town beggar (Noster Eagle-Eye) out front of Radiant Raiments. Add this to a fortify barter necklace, thieves hood and a fortify barter potion and get the best prices. If Speech is less than 80 however, getting the blessing of Dibella (which can also be done by visiting Endon in Markarth instead of Gulum-Ei) will help, but that will likely not be able to max the discount yet. There are a few other items to fortify barter and Speech outside of the necklace and hood/mask, but they are unnecessary unless Speech is less than 90.