Well, this morning I get an e-mail from the seller saying:
I'm not sure what to do (I have contacted eBay for their suggestion), since I really didn't need the cards in question, so would be willing to "let him off the hook" when he returns my payment (which, notably, has not happened yet), but on the other hand, if you're going to put something up with an opening bid under a buck, you'd better be steeled to the possibility that the auction's going to go for the minimum. I'd really rather not be an asshole about this, but I can't see how to not at least leave highly critical "neutral" feedback. His case would have been stronger had he "bounced out" my PayPal payment when he decided to try to weasel out of the sale, but I guess at 8 "points" and only being on eBay for a month, he might not have a clue about that ... this is also the first time he's sold any cards (although he's bought one), everything else has been automotive stuff, some of which sold well over the minimums."... I would like to hold on to the item. This was one of the first times I have used ebay and I fell a need to hold on to the cards.I was not happy with the price. ..."
Damn. If this was some kid trying to move his just-grown-out-of card collection, I'd feel bad for being an asshole about this, but (looking at his sales history) I'm guessing he's an adult (would a kid be selling a go-cart engine with an opening bid of $350?), and is just trying to duck the auction.