I purchased the second one down on Snowmad's list for $3K from Bigdawg1974. He had it listed for a couple/few weeks before he accepted my offer. My guess is that you can reasonably expect somewhere between $3000 and $4500 for one in good to very good condition.
Your location relative to potential purchaser's location combined with the color of your trailer and the color of purchaser's van will dictate final price...