uh, for wiring from a computer based cabinet, you really only need to hook up two microswitches to the same place you'd hook up your coin buttons, and if you want to hook up the lights, you just steal the voltage from a molex connector in your computer. there is no wiring you can't handle in this situation, mostly if your going to build an arcade cabinet. as for a coin door, you can get one off ebay, but they don't cost much less than new and they ususally aren't perfect. just give ponyboy a ring.
also, why are you making an arcade cabinet if your worried about the money? mine has cost me over 1500 and it doesn't even work yet, although over winter break, i hope things will change.