I am looking to purchase a used ZTR mower, probably something in the 48 to 60 inch range. My question to hours on a used machine. What would be considered high hours, and how many hours can you generally get out of a machine with proper maintenance? I am not a full time operator. I recently got a contract to cut 8 small city parks (about 1/3 to 1/2 acres each). In addition, I have about a dozen residential properties that I could use the machine on. Any advice would be appreciated.