From my understanding Europe used alot more Amiga/Atari ST computers then in the US. Just like the US probably has more mac users (and apple II's I would imagine) then europe does.
The amiga never really caught on in the USA hence you dont see alot of amiga equipment for sale here (except the 1million 2000-3000's with toaster setups that are always on auction on ebay for crazy prices that never sell.
I do remember one shop that sold amiga's (2000 model i think for real work) but nobody I new had one and they were expensive at the time. Generally people used IBM type pc's for gaming starting in the late 80's early 90's. Most of my friends went from c64/128 to PC's (one was an atari 800 user instead of C64 and suffered acordingly from lack of games in the late 80's)