Not too long ago, I sold a classic / vintage education textbook for $99 (the book usually sells in that range). The buyer (who had a low feedback rating) said the binding was little loose and demanded a $50 credit. I said no, send it back. She wanted the refund first. I said no, and ebay said don't refund until you get it back. I fully expected a box of moth balls back, but she actually sent the book, and the binding was fine. I don't know whether she photocopied the whole book for reference, or just had buyer's remorse.
A good place to keep track of ebay adventures is: www.ecommercebytes.com
ebay is going to be even worse when they start the 180 day refund stuff, students will buy textbooks at full price, then return them at the end of the semester.
And 'managed returns' will also be required next year, where the buyer only has to print a label to ship the item back and the seller will have to pay shipping, whether the shipping is for a textbook or pinball machine. And to make things worse, for "Top Rated Sellers" any return is counted as a 'defect'.
As sellers already know, you can put SOLD AS IS in large font in the listing, but with ebay's policy the buyer can still get the refund by sending the item back SNAD (significantly not as described) no matter how well you described the item.