…so now I want to build my own. Check out this excellent and well-reviewed set of instructions for building a mame cabinet. Not to expensive - leaving out the cpu and monitor my guess is this cost well under $300. This is going to be my spring project, though I will probably go with an lcd monitor and a small form factor pc to power it.
There’s also an extensive set of plans for a variety of cabinets here:
http://arcadecontrols.com/arcade_cabinet_plans.shtml#Jeff_Ultimate
if you’re interested.