You have nothing to lose trying Craigslist first. Just give a complete description with lots of pictures and be prepared to screen the buyers from the lookers. I've had good results with Craigslist selling motor homes.
Next you can try eBay for under $100. Again, give a complete description and lots of pictures. You can set a realistic reserve and if the bidding does not reach that amount, you do not sell. What this MAY do is give you an accurate idea of exactly what the coach is worth. I've sold some high dollar Classic Cars on eBay and things went smoothly.
If those two places fail you, than you may consider the places that want to charge you a consignment percentage.
Personally I've never had much faith in the consignment dealers. After all a quick sale, at whatever price, still nets them a commission. There is not much incentive for them to hold out for a higher sales price.