There's actually a couple of guys who have posted on Kickstarter to try and fund mass production of something like this (without the "virtual marquee" I believe). Why is it that people keep coming out of the woodwork thinking they can make $$$ off of MAME?
because that's human nature, people will try to make money out of anything they can, any way they can and simply take advantage of the hard work of others.
meanwhile you have developers of the actual project who are struggling to get by (can't even afford to replace their machines) and do everything for free, but don't complain nor try to make money out of it at all.
as I've said in other threads, the Pi won't give you a good experience, it's severely underpowered and can only just get by with ancient versions of MAME which were buggy and offered much lower emulation fidelity, such projects don't even make MAME look good.