Price aside, a robocop game is a good game to preserve, but NOT to mame. First off the robocop dataeast cabinet was only usd on a select few games (robocop,robocop2 and the "parent" game bad dudes.) It's unique shape and curved marquee make it a collector's item. If the cabinet you are looking at does not have a curved marquee then it's not a robocop cabinet and is pretty much worthless without a working monitor. (robocop pcb's are a dime a dozen) If it is then it's worthless for mame anyway. Why? Well for one thing it has a heavy gauge steel cp. This cp is also very narrow, meaning that it would be quite difficult to put more than 3 buttons on it a piece and not be right against the monitor when you are playing, not to mention actually cutting through the thick metal cp. It can be done, as the original sf2 had a similar cp, but it's not reccomended. (Even capcom quickly changed to a larger cp in later revisions of the sf2 series) It doesn't sound like your are going to mame it, but I just wanted to warn you.
It is a rather collectable cabinet and to a robocop or dataeast fan it's worth it, but if you are just wanting it to mame then it's probably not worth your time.
Hope that helps