Search the net for reviews of guns which interest you. While I believe more buyers will post negative experiences, their poor experiences wil at least provide you with some general expectation of reliability. Please do not, as I did, ignore the preponderance of bad experiences and expect to "get a good one".
While it is true that you get what you pay for, even the high dollar manufacturers can produce questionable quality firearms.
But, help us help you: are you limited to semi-autos? a particular calibre? finish?
On your first point, I was just hoping to avoid the back-and-forth of good vs bad experiences with common guns (e.g. some people love Glocks and some seem to hate them). If multiple people have something bad to say about a particular gun I will definitely strongly consider it.
Not limited to semis, a calibre or finish