Since there is no legal way to buy the ROMs, most arcade machines have been recycled and trashed by now, it isn't possible to buy the original arcade machine, and the only way to play these arcade games now is via MAME, it seems as if piracy is the only way to get ROMs until someone gets permission from ROM developers to sell their ROMs.

MAME has thousands of ROMs and games, it would be near impossible to get a license to sell each and every ROM.

StarROMs tried that with the Atari arcade ROMs but failed.