I've sold three guitars on eBay - a custom classical guitar, an acoustic/electric bass guitar and a G&L ASAT (bit like a Fender Tele) - and had no problem whatsoever. All good, honest buyers and good payers. Packaging was a pain - wrapping a solid case in plastic and tape took for ever - but all went OK.

I've only ever bought one on eBay - and it was a 1961 Otwin, an East German jazz guitar by luthier Othmar Windisch - just because it was like one I bought in 1968. It was as cheap as chips, and I fitted it with a floating Kent Armstrong mini-humbucker p/up - sounded sweet!