there is not too much that can go wrong on a 3ph winch. i own a fransgard 3ph winch and they are simular to farmi. the clutch operation is what i would be most concerned about. if the previous owner slipped it a lot that might cause you some headaches later. ask the dealer if he can hook it up to a tractor so you can see it work. check if the clutch works good under load and while you are at it check the cable. make sure it is not freyed, etc. other then that i can't think of much. look it over and if the rest looks ok, it should be ok. most winches are just about bullett proof. as far as price, i don't know about the 501 model. my V-3507 is a 7000lb + winch and i bought it new for about $3600 just to give you an idea to compare. there are a few others here on tbn that have farmi specifically and hopefully they will chime in.