$60 gaming PC's are doable if you buy an "untested" Dell Optiplex and get lucky. A few years ago, I bought a couple of these in that price range that not only worked, but had a GPU of some kind. Good enough for Left4Dead at least, and some other Indie games. All they needed was an HDD with Windows 10 (both of which I had lying around - Win10 licenses can be had for a few bucks).

As long as you only want to play games from 2008. :)