I mostly remember seeing reviews of Neo-Geo games in CVG UK when I was a kid, and remarking at how insanely expensive they were. I think one game was something crazy like 300 pounds of 1990s money, so probably about 10,000 pounds of today's money. When I moved to Japan I would see the same games on sale used for about 500 yen, which was about 4 pounds at the time.
Neo Geo was one of the first systems I was really into playing on emulators because of how much we all desired them as kids and because they played great even on my ancient Pentium 200 back in 2000 or so.