I'm saving a lot of money by not having to buy a PC. Over the years I've probably collected enough bits and bobs to build 2 or 3 PC's, so I've put all the bests bits together and stuck them in a case to make my Arcade PC. It's not a bad little machine too! Although the 20gb hard drive that Windows is installed on seems a bit iffy, so that might need replacing. It's got a 80gb HD for ROMS/games too, and I'm not quite sure if that's going to be enough. We'll have to wait and see :)
One thing I will have to buy though is a new graphics card. The onboard one is perfectly fine outputting to a monitor, but my cabinet is going to be running on a TV so I'll need a graphics card that has TV out. I'm sure they're not much though.
I've got it setup temporarily on my landing. No idea why there, cos it's not exactly the best place for a PC, but ah well :P It's Windows XP on now plus a few games (Street Fighter II Turbo in the picture) and all seems to running well :) Not sure if it'll be staying in that case though. Might put it in a different one.