MVS prices are not high. A once $700 cart going for $100 is not high, especially compared to a once $300 cart going for $5000 like on AES.
One very effective way to save money is to buy beater carts. Most of these new MVS guys want pristine everything, "complete kits", etc. Who the hell wants a "complete kit"? It contains stickers you're never going to use, a plain cardboard box, a piece of bubble wrap...these are a pretty poor excuse for a collectors item, IMO.
Anyway, the "complete kit" people don't want the rough stuff so you can buy stuff super cheap if its ugly. I bought a filthy-ass Real Bout 2 cart from Mexico for $15. To me, the fact that it saw 15 years of service in an arcade makes it far more legit and real and SNK than some pansy-ass plastic-wrapped collectible, and I saved a considerable amount of money.
And, for the record, I like a lot of old Neo games. League Bowling and Super Baseball 2020 are some of my favorite titles. The thing is, a non-wealthy AES collector is, effectively, buying a machine that can't play anything made after 1994 and thats a f*cking tragedy to me.