You didn't mention what the guy was going to include with the boat. A trailer will run you about a grand to 1500 as they are difficult to find used. Also does it have an anchor system, anchor, oars, heater(s) rod holders, fish box etc. You can spend another 1500 bucks just on the stuff to make it fishable. If the guy is leaving town and all of this is comming with the boat be sure it is the same sort of stuff you would install. Figure the boat at 75% of the new price and all of the extras at 50% of new. Without the trailer though I wouldn't venture to spend over 2500 for it as you can get a nice used boat with a trailer and lots of goodies for 4000 bucks. Good luck and watch out for the rocks in that glass boat. Rogue Runner