I don't think it really matters what kind of money you have in it, unless it is a full blown race bike. I had a Z400 that I got in Nov 03, sold in Oct 04. Had a pipe, filter, Beadlocks. Only got 4k for it. Owed $800 more then I got for it.
People don't want to pay big money for used quads. Its a fact. I wouldn't want to puy 3-3500 for a 2000. I could buy a new one for 6. They just don't have resale. There are too many of them. Now if you are trying to sell a Stock 250r or something, thats a different story. Don't mean to put you guys down or anything. Thats just my view.