At the risk of comparing apples to oranges, I thought somebody might be interested in the rough costs associated with getting a Supergun + Neo Geo MVS setup together. Below are USD costs of the main components for the system which I put together over the course of the last month or so. Obviously your mileage may vary and you may be able to source some parts cheaper and get better deals in terms of shipping costs depending on where you are located, but this should give you a rough idea of what it takes when putting together such a system from scratch.
ArcadeForge Supergun + PSU 171,43
MV-1FZ board 115,01
Unibios 3.1 35,34
161-in-1 cart 97,65
Euro SCART RGB cable 3m 20
Jamma extender 34,1
2x 5m gameport ext. cables 22,94
2x Neo Geo CD pads 100
2x lithium recharegable batt. 10,54
Total 607,01
All in all the costs do rack up. A possible saving would be to go for a cheaper / lesser quality Supergun, although I must say that I think this was money well spent. People in the US would usually also require a video encoder so this is an additional cost to factor in.