This is the site you want to check out carefully for all M100 questions/issues:
http://lotuselancentral.com/index.htm
Price sounds OK if car is clean--you might want to confirm with a carfax report, though.
I had mine for over 5 years and only gave it up reluctantly to make space for the Noble. I have driven all Lotus models, current and "classic" and, IMO, the M100 is by far the most underrated car the factory ever designed/produced.