Call on a new one of the same model with the same options and see where that's at as a comparison. In addition, check online to see what pricing you come up with over a range. I've checked Craigslist and Tractorhouse.com to see what others are asking. Tractorhouse are primarily dealers so they are going to be higher than a private seller.
Should be able to get you a pretty good ballpark price range. Tractor pricing also varies by region so keep that in mind as well. Doesn't seem like a bad price to me, but it also depends on condition and what you're willing to spend or can afford. If you "need" a tractor soon, that may determine if that's a decent deal based on having to wait and what it will cost you, or by getting things done sooner that need it.
