Simple parts inventory program? (free or opensource)

This is the only program I know of that does inventory management: http://www.trilogydesign.com/

$99 bucks for the cheapest version.

I’ve written a program that is similar, to better suit my needs with mysql as the database engine. If I get a huge push for something I could possible make something for cheap ($40 bucks) with a free version with limitation. Does anyone know of something out there that you can actually pay for?