I have a a Japanese prototype of the Mega Drive game, NBA Jam for sale. This cartridge originally came from Acclaim Japan. Before it contained NBA Jam it had T2 Arcade Game on it.
I have no idea how different it is from the retail game but I have tested it and it does work although every now and then it may crash and show a bug report as seen in the photo below.
PRICE - 5000 yen (Includes well packed standard airmail shipping, NO tracking)
PRICE - 6500 yen (Includes well packed recorded airmail shipping WITH tracking)
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