I sold my last car (Audi TT) and last motorbike (Ducati 748) on eBay as a classified ad. Think it was £19.99 for a 28 day listing, which ain't bad for a globally known site with a very high number of users/visitors.
Put a good, honest description, plenty of photos and set a realistic price, with a 'best offer' option and both car and bike sold within a week. I had an offer of a deposit on one after 3 days!
As said above, just ignore the idiots. You can set an automatic decline on any offers made below a certain value, so you won't have to bother with those anyway.