Update:
Short Version: I ended up meeting a great guy and hauled home a "needs work" compressor for $100.
Long Version: The compressor had been sitting in the garage unused for about a year, it was left in good working order (I actually really believe him, seemed like a real stand up guy), but when he hooked it up for me to hear run, it would start up and then about 15 to 30 seconds later the motor would kick off. The breaker was not tripping, I was thinking thermal overload or bad capacitor(s) it has 3. I don't know a lot about electric motors, but even at the worst case, I buy a new, bigger motor for <$300 and I get a great compressor for under $400. My hope is that it is just a bad capacitor or maybe a rewinding. We will see. I figure it was easily worth $100 since the compressor and tank seem to be all good.
What do you think?