what year model is the baler?.....first off a set of new belts will probably run you at the lowest $400 give or take a few bucks. this is just to start with. What to look for.......ask about the pick up on the baler, (what grabs the hay off the ground) look at it real close, ask if it has ever been gone through or had anythig replaced, bearings, etc, look at the rollers on the inside of the bale chamber, make sure they arent bent up, cracked, have been welded on, etc, if the baler has a slip clutch look it over real good, if it is jsut a shear pin setup then not as big a deal,.....make sure you can get parts and service for the baler in a timely manner. if you have hay on the ground and the baler breaks and there are no parts and sevice to help you get going, your hay just burned up out in the sun.....not good.......i would personally try to find a new holland round baler, New Holland started the hay baling industry so they know what they are doing, if it is a used baler you are looking for try to find a 600 series new holland. let me know if i can be of any help.