From my experience trying to get spare parts, you wont be able to piece an S7 together for less than what they are going for right now (1200-1500). Each board in working condition is selling for ~$550-600, controller board for ~$100-200, I/O ribbon cables for $15x3, then fans (not sure on price). Better off finding a solid working unit.


Another possibility is finding the "broken" boards that actually just have bad PIC's and soldering on the potentiometer that is in a fix thread on these forums. They usually sell for under $100 on ebay.