How about I finish this topic off, once and for all.(posted 9242 days ago)http://www.twingalaxies.com/Rules1.html
If I may quote from it:
"1.2 One-Credit Games Only No buy-ins allowed. Barring exceptions that are individually listed in the difficulty settings of each game, scores are accepted only on one-credit games. Games that allow or even encourage multiple buy- ins have to be dealt with on a game-by-game basis.
Buy-ins, unfortunately, produce scores that reflect a persons wallet and not their skill. Most modern games feature buy-ins and some dont even award the player with a score at the end of the game. Buy-ins are absolutely ruled out, except for a few games like Area 51 or Maximum Force which produce an inevitable ending despite buy-ins."
So yes, there are some (ooo, he's experimenting with HTML, that's not good :) ) games that allow buy ins. I don't know about any in MAME that allow them, but some games do allow them. If I find anything else, I'll bring it up.
Sincerely,
J.D. Lowe