i just priced out some hardware for a friend of a friend today, to do a 4 player panel, six buttons for players 1 and 2, four buttons for players 3 and 4, four 8way joysticks, dedicated 4 way stick, 3" trackball, spinner, control interfaces, and a few extra buttons for coin/start/exit/pause and a few for near the 4way stick,...once you counted in shipping, the total came to around $380. that is just for the controls, (basic controls, no light up fancy stuff)when you factor in the wire, crimp on connectors, wood, tmolding, artwork, plexiglass...and the time it takes to fabricate something like this, $770 seems pretty reasonable to me.
personally, i say build your own, but if you are going to buy, those prices seem reasonable....i would however avoid the lighting upgrades...just a waste of time. you can always add that stuff later down the road if you decide you want to spend a bunch of money again