I've had a couple of decent results on eBay lately but the commission/fees is really getting a bit rapey tbh.
I did have 1 absolute joker last year though. I sold an abandoned TT project - frame, wheels, seatpost, front aerobar set up for just under £1k, which was ok but not great. It was accurately described with good, honest pictures, and I'd been hoping for c.£1200.
Anyway, the winning bidder arranged to collect in person - and on arrival picked over it for literally 15 minutes, finding tiny/imaginary marks, trying to haggle all the while. I told him he'd won the item at a set price, which was probably less than it was worth, and if he didn't want to pay it he was welcome to leave it, but I wasn't discounting it.
Given he'd driven 2 hours, I figured he'd see sense, but it was another 20 minutes and only when I gave him the ultimatum that he either needed to pay as agreed or leave, that I finally got the cash, and then... when I counted it in front of him it was £50 short!!!!