satnrose, Amen to that. When I opened my very first brick and mortar used bookstore many years ago it took about a year for the customers to cherry-pick my inventory and I was left with nothing but junk. It was a costly lesson.
Now that I have a better idea what to look for I go cherry picking in other people's bookstores.
One big no-no is to not specify shipping costs in the auction listing. I have an auction I won a week ago and so far three emails to the seller asking for shipping costs have gone unanswered. It's just a book, how hard can it be to mention the shipping cost. And his listing says pay with PayPal and get it sooner. Yeah, right! How can I get it sooner if the seller takes forever to answer a simple request for the shipping cost? Very annoying. I think that from now on I won't even bid on auctions that don't list shipping cost up front.