For that kind of money you can get a nice Bronica ETRS or Mamiya 645. Check Keh.com for those two cameras. If a fixed lens doesn't bother you then a Yashica TLR or even a Rolleicord is doable on that budget.

Me, I gambled and bought a used Yashica D from eBay from a "I don't know much about cameras" type. I got lucky and got one in working condition. Later when I picked up a Rolleiflex Automat the same way, my luck wasn't as good. It worked fine for a few rolls then the shutter started sticking on the slow speeds. Mr. Ebel sorted that out for me by replacing the main spring but it cost me $170 on top of the $100 I paid for it. This can of course happen with any old camera you buy. Buying from a place gives a 60 day warranty or better is advisable.