This is the cheapest I've found: http://www.koalamotorsport.com/.
Prices aren't listed, but apparently range from $2400-3400 according to SilverStreak on BFc. A rainbow of ratios it seems, too.
That's still pretty damn expensive though. I'd put it in the S/C fund. Then again once you get the FI, you'd be peg-legging even worse than before. LOL, have fun with the E46 catch-22.