i'm going to say it's perhaps a bit too much, based on the presumption you are talking US dollars. my assumption is based on the fact that everyone else bothers to mention which country they are in or which currency they are talking about.
Not bad, prolly gettin a lil long in the tooth (P4-Ms sucked), but Thinkpads hold up like a tank through the years. I just sold a Dell 600m for $425 if thats a good reference for ya. Check eBay, thats the best used value gauge.