[BillyCoxDodgers3B]

There were a series of issues here, but the entire thing has its roots in some of the cards being overgraded. Were clear, hi-res scans or photos provided pre-sale, along with proper noting of any blemishes that the scans failed to pick up?

Regardless, the buyer thought he was getting something different than what he signed up for. Upon reinspection, the seller agreed with the buyer's condition assessments, so they have admitted that oversight. Since the original error rests on the shoulders of the seller, a better compromise than "all or nothing" should have been granted by the seller. Seller is the source of the initial problem and completely fails to bend a bit as the result of his oversights. Hence, seller is the bigger problem.

Also, the buyer is clearly only interested in cards of a certain condition and wouldn't have added them to the discounted deal if he had known about the issues.

Personally, if it wasn't a ton of money, I would have likely acquiesced to the buyer's wishes and moved on. Not worth the time or aggravation. If not:

The easiest solution? Simple. Meet in the middle. Crunch the numbers between the full and discounted prices and offer the remaining cards at whatever that happy median turns out to be. How hard is that? I can't see how anybody would take issue with that logic. If at that point the buyer says, "No, thanks", then it's time to just give a full refund and move your merchandise elsewhere. The seller would have done all they could as far as I'm concerned.