Check out arcadecontrols.com. They have lots of info about building and configuring MAME cabinets (and other emulators).
As for pinball machines, I have one, and to get one in good working condition expect to pay at least $600. For something like TNG, or any other popular one like Black Knight 2000 or Addams Family, you'd probably pay $2500 to $4000.
I bought a fixer that was not a popular one (called Motordome), paid $300 for it and put another $75 or so in parts into it to make it 100% working.
As for pinball machines, I have one, and to get one in good working condition expect to pay at least $600. For something like TNG, or any other popular one like Black Knight 2000 or Addams Family, you'd probably pay $2500 to $4000.
I bought a fixer that was not a popular one (called Motordome), paid $300 for it and put another $75 or so in parts into it to make it 100% working.