I don't know what's fair for your area but that's a steal compared to what I've been finding in the used market around here. Assuming nothing major wrong with it. Around here people would probably ask $10k-15k, maybe $20k with attachments.
Sounds like a deal, see if you can use it to dig a hole or something and make it hot to make sure the hydraulics don’t get real slow. If it does then you can afford to work on it for that price but make sure it checks out first.