I recently sold a 2011 Gravely Pro-Master 260, Kawasaki engine, with 630 hours in excellent condition for $5,000 so it is doable in your price range if you find the right seller. Those mowers through the dealer seem a bit on the high side, with that many hours, in my opinion. Of course, you can expect to pay more at any dealer than a private party sale. Good luck.
Dependable Mowing Service