i use the same pushbuttons that i use for the rest of the controls. i have this on 2 of mine, plus external on/off buttons and a pause button on my neo-geo. how big is the hole?
probably just means you need the wiring and the slot since the board should have the connector. i dont think i know anyone who uses their card slot, nor have i seen a working card.
i have an nba jam cab where i made the CP a bulls vs. knicks theme. i think it looks pretty badass. it is professionally designed and printed though, not just thrown together with some leftover paint like the longhorn cab.
there's a pool table store near me that has a few arcade machines and pins on the floor. they don't sell a lot, but they do sell. the sales guy basically said, when a rich guy comes in to buy a $10-15k pool table, convincing him to buy a $4k simpsons pin is easy.
as for regular sellers, yeah...
if you know the price you have in mind, just post it. i don't know what any of those machines are worth. now imagine i'm a guy who's just looking for some machine he played as a kid. now i really don't know a price. if you want to sell to collectors, do so, but CL is not the place for that.