I've been lucky, but that's mainly because most of what I buy off the bay is beaters. 7 bucks for a '67 T-bird with missing W/S posts and windshield, 8 bucks for an old Lincoln missing bumpers, lots of stuff like that... I could never get myself to buy a valuable collectible without seeing it in person, actually holding it. I feel the same way about selling... the one big slot sale I ever made (sold an orange mako for $700) I did at a show. I cringed at the thought of selling it on the Bay and it getting damaged in the mail or some bozo with a junk one opening the box and switching it for his beater and then demanding his money back, claiming that I sent him junk...
I did have good luck selling my old Buick wagon on the Bay. '92 Roadmaster Estate Wagon. 180k miles, transmission went. I posted a laundry list of stuff wrong with it and listed it for $100... worst case scenario, I'd get one bid and just cover auction fees. My wife thought I'd be better off getting 50 bucks from the local junkyard. The winning bid was almost 600 bucks, the guy had zero feedback... i had a bad feeling, but he sent me a MO for half right away and showed up with the other half in cash the following weekend, along with a big honkin Ford pickup and a trailer. Funny ending to the story... just now I checked the completed auction because I forgot exactly what it sold for... the guy now has 3 feedbacks. His most recent transaction was selling the car he bought from me, but with a working tranny that needed to be installed...
--rick