First, I'm not selling anything. I found a walker model #mcghs serial #91-10392 with 42" collection deck and 16hp Kohler and the guy said it's a back-up unit for him and he'd sell it to me for $500.00 to help me get started in this business. Is this unit so old or obsolete it's not worth getting involved with? I rode it around his parking lot and it seems to be fully functional, except when backing up it tries to buck me off. What's up with that? Other than needing a paint job and a couple of tires it seems to have been very well maintained.It has also been very well used.This unit has seen more hours in a week than I will probably use in a season. I thought this might be the only chance I would get to afford a walker for a while and after doing some price research I haven't seen one below the 4 digit price range. Thanks for any advice.