We've bought two diesel pushers on ebay. Both were repo's, from small used RV dealers, and fundamentally as advertised with a few little glitches. My approach is to thoroughly research the real market value, which doesn't mean asking prices... It means SELLING prices. Then I bid up to about 80% max of what I estimate the true current market value to be. That way, if I buy it I've got good room to repair unknown problems. Even if you really inspect a coach well before you buy, chances are you'll need to do some repairs, upgrades etc to it.
Selling, I don't recommend ebay. Do a search of completed listings, and you'll find the vast majority of RV's do not sell. Most folks are too afraid to buy an RV on ebay. Each RV we've sold, has been on RV Trader. None have taken long to sell because we have priced them in accordance with true market value, and presented them in absolutely like new condition.
Virtually every coach I've looked at via private party (and most dealers) is either overpriced, not spotlessly clean, or both.
2012 Montana 3582RL