Long story short: bought a RZ67 Pro II + 110mm lens on eBay in excellent cosmetic condition for $700, kept it in storage for 6 months (first bad move). Description said the seller was not a photographer, friend gave it to him, and it had been sitting in the closet for a long time (red flag apparently to experienced people, but gullible me had no idea at time of purchase). Shot some rolls with it in a studio setting only using flash and 1/200 shutter speed and everything appeared to work fine. Then, I tested it out outdoors for once, using all varying shutter speeds available and (there was a url link here which no longer exists). Strange, so this whole time everything has been shooting at 1/400th speed (even in a studio) and I didn't notice because I never tried slower speeds.
Made a video on this for proof. Repair shop inspected/tested it, and they said the lens is working fine, but its actually the body that has a damaged circuit board which replacing (parts, labor, etc) could cost anywhere from $320-500 depending on if it needs an "old" or "new" board, as a new one would have to be ordered from the manufacturer and cost more/take more time.
At this point I'm really bummed out that I had to learn this lesson the hard way, if you're going to buy a used camera thats been sitting for a long time it MUST be inspected and serviced/CLA'd. The guy there (at Nippon Photoclinic in NYC) told me it would be best to put the money into repair so you know the camera is a working one rather than buying another one on eBay and being uncertain of it's condition. I'm not sure what to do, what would you do?