I bought my 2002 Insight yesterday with 125k miles.
Through my searching of Insight for last 2 months, $2500 for 2001 Insight is very good deal if it's running fine without any problem. It's out of battery warranty but I heard that you can replace them or recondition them for $1000 or so.
I initially thought I was making mistake on purchasing. I felt like I was asleep when I was making my final decision.... but once I started to drive and saw the mpg, it just confirmed myself that I made a good decision.
Good luck with your purchase. I really wanted manual but I couldn't find anything in right price range so had to go with auto...