I really haven't set a budget. I've been picking up components as I find deals on them. I bought a TV turner card, and a DVD burner a while back on a deal, and I've got this left over memory. Have been watching for a nice HTPC case, haven't jumped on that yet. I want something that's quiet, and the last system I built used a passively cooled vid card. Thought about that again on this one, but really the on-board might work just as well.
I had planned to use this as a time-shifting digital video recorder, but I've since bought a Phillips HDD/DVD recorder, so that's not a big deal now.
Doubt if there will be much gaming on it, if so would be nothing taxing. Mostly to access MP3 files. It will be hooked to my 42" lcd TV, via VGA, so whatever video would need to support that.