u could get a consolized MVS.
it's probably possible to modify an AES board (and add chips to it), to get it to run an MVS cart in an MVS slot (that has been wired to the AES slot). But it would be very difficult to do, especially since schematics of the AES/MVS haven't been released.
Kpj had a prototype 2-slot board with one slot being an AES slot. Don't know how well he had it working though. If he did have it working 100%, he would have probably made a big deal of it, which he hasn't.
So basically the cheapest way for me to start collecting NEo Geo games is to go for a one-slot right?
probably the cheapest would be a 1-slot and a Vogatek supergun motherboard. but a 2-slot has more of the same features the AES console has, u could either get a consolized 2-slot or a 2-slot and a supergun, maybe one of the better ones like a MAK. The members here can tell u what consolized MVS's or superguns to get.