That is a decent price assuming the tractor is in nice shape. If the tractor has been serviced appropriately I would not be concerned about the hours.
Mine would look the same as well. Some of the best little engines Kawasaki made in my opinion. Unlike both my X530's, oil goes black after only a handful of hrs.the '03 GT235 I had and father-in-law still has has well over 500 hours and hasn't shown any signs of fatigue or wear. The oil goes in amber and still comes out amber and we only change it once a year, about 40+ hours a year. I was always very pleased with that Kaw. If the rest of the tractor is in good shape, that's a buy