my friend, trust me on this....there is no such thing as a cheap boat! having said that, i'd seriously consider the trade but look it over closely beforehand. check for soft spots, cracks or squeezing of the transom where the motor mounts. look for fiberglass cracks or openings where the deck meets the transom. open up the top of the motor hood and check the wiring for cracks and general degradation. bump the motor over. check the compression, run it if at all possible by hooking up some cooling water and jumping to start. check the flooring in the boat cockpit for rot, cracks, soft spots etc. check the hull for cracks or splits, especially along the bottom and where the deck meets the hull. if the engine is good, or can be repaired cheaply, i'd say you've got a good trade. the boat hull itself can be cleaned up, repaired etc with the exception of the transom. transoms can be fixed but can be a big job you might not want to get into. having said all this, if the boat seems tight, you'll be able to get some fun out of it but don't look for much in the way of money when you decide you want to move along. if the engine needs work, i'd pass because parts ain't cheap. other members here have done amazing work on older boats and it's a labor of love. beware of cheap boats that need to be scrapped.
good luck.
