I'd say around $50 is right. I lucked into a sick eBay deal... The SVC Chaos JAMMA PCB, 2 brand new Happ Ultimates and 10 brand new happ pushbuttons w/switches & nuts for $26... plus $15 shipping. RIDICULOUS. I feel bad for the seller, they are super nice and super good and deserved much more for that auction.
EDIT: This post isn't meant to imply the value of the board, just that I got incredibly lucky on an auction and I wanted to brag.

The board is probably worth $50-100ish.
I think I saw one on eBay with a BIN of $69.99 recently.