delta123 said:your best bet is the side streets. there are a lot of second hand resellers there. i bought my ps3 from a 2nd hand seller. and i trust them with everything. japanese people look after their stuff.
your best be is to find the KFC in akiba and across the the street from it. (it is a small ally) there is a 2nd hand games store. will have a GBAm and all the games you need in there.
Its funny, cuz ive only been to Japan once, but I clearly remember Akihabara, and know EXACTLY where that is.... Weird to here someone talk about a place half way across the world from me and to know in my mind the exact location of the place.