Used Tractor Values

Rather than purchase a new unit I’m looking for a used one–I like the Kubota tractors–they appear to be of a comfortable size. These units are expensive and I am looking for a used unit of some type. Some say, stay away from those tractors that are hard to get parts for as-Mitsubishi, Ford etc yet these units are the most common in the used market under 2,500.00.
I can purchase a used (2yr. old),Husqvarna lawn tractor , 21hp w/48″cut for $900.00–is that appropriate-for 2.5 acres?