This is still the greatest thread on the board!
I have recently moved so haven't been here lately, but thought I'd share a few of my recent looks-like-nothing sales:
Sky Soldier by Lawrence D.Okendo, a PB about a man who served in WWII, Korea, and Vietnam. Got it for .25 at a yard sale, sold for $100 online.
The Teacher of Greeting Cards of All Kinds by D. M. Campana, PB, a quarter at a yard sale, sold online for $65.
Through the Eyes of Number Two by Mickey Guidry, about playing backup QB for LSU, 10 cents at a yard sale, sold online for $50.
All those sales came this month, but I'd had the books for much longer. Just goes to show there is a market out there for just about any book if you can wait for it.