How much should I ask?
Putting an unrealistically high price in your ad will almost certainly mean you'll waste your time waiting for the phone to ring, but put too low a price in it will have you rushed off your feet by tyre kickers hoping for a bargain.
In the weeks leading up to running your ad scan the www.racetrailer.com website and get an idea of the prices being asked for similar race trailer as yours.
Selling your race trailer directly to a buyer can be an excellent way to get top-Euro. Many race teams done it lots of times.