It does come down to how much time and money you are willing to spend...

Just restoring the cabinet and artwork itself will be very time-consuming and expensive...

Then if you want to go with all original hardware, you will have to find parts on Ebay or the forums, and hope that you can figure out how to hook them up...

... and hope that they all work

when you put them together...
I bought an old Robotron cabinet that had been converted to a JAMMA game. Not many original parts were left and the cabinet was in horrible shape. The harness was all hacked, extra holes in the CP, etc.
So what I ended up doing was:
I fully restored the cabinet and artwork. Then I used a retired PC and an ATI Radeon 9250 card and Powerstrip installed to run Robotron in CGA resolution. Works for me!!! Check it out:
http://forum.arcadecontrols.com/index.php?topic=63639.0I estimate I spent about $650 for the whole project, and the result is a totally Mint Robotron machine in my gameroom!!! Plus I had a lot of fun restoring it, and I learned so much in the process. Well worth the price.
I plan on doing something similar with a Tron cabinet I have in the garage, which has a few more original parts in it. But the transformer is rusted out, the cabinet is really dirty, and I am not very optimistic that the boardset works...

So I will restore the artwork, then use a dedicated MAME box to run Tron, and maybe Mad Planets and Arkanoid.