If you have the knowledge, you can build your own supergun quite easily if you can get hold of the right parts for it - I'm not the best person to ask about this though, try asking on the tech forumUnderdog:
How does a Supergun compare to an AES system in cost?
. Professional ones like Mas Systems super Nova cost around $300 or so... depends on what you go for really. Bear in mind you'll also need to buy an MVS motherboard too to be able to play any Neo Geo games.

Hey man, I like the labels of your carts. Where are these from? Did you printed them using current paper?Mysteriozone:
Check out more pics of mu Supergun here:
<a href="http://www.mysteriozone.com/NeoGeoSuperGun.htm" target="_blank">http://www.mysteriozone.com/NeoGeoSuperGun.htm</a>
Those are my cart tag templates you used on your carts. Wow, someone likes my work. cryingMysteriozone:
Thanks!!
I got the labels from Kazuya's neogeoforlife.com
site. Then just typed in the name and meg size in photoshop.
Makes it all worth while. Thanks Kazuya for hosting them. 
Sorry to go off topic but Jhendrix hasn't sent you any of his new covers has he?Kazuya_UK:
Yeah it's great to see any of the stuff that's hosted up on the site being used - that's what it is there for![]()
Nice setup you have going there man, very nice indeed buttrock
Nope not yet - we did talk about it but I think he was going to sort out hosting with someone else. If he can't get them hosted anywehere I'd be happy to post them up for him thoughFrasermozz:
Sorry to go off topic but Jhendrix hasn't sent you any of his new covers has he?Kazuya_UK:
Yeah it's great to see any of the stuff that's hosted up on the site being used - that's what it is there for![]()
Nice setup you have going there man, very nice indeed buttrock
