Buying a used 1911 means you are the one who fixes it. I've mostly had good luck buying used but the Ruger is a very good pistol, by all accounts.
Ruger, Springfield, Leupold, and some other mfg's will warrant the item if it has their name on it.
I have several Rugers, but for 1911 Springfield builds them the way they're supposed to be built. You should be able to find a Springfield Mil-Spec used in your price range. Used is still covered by warranty.
I've purchased dozens of used firearms, from pawn shops, gun shops, etc. Mil-Surp from Big 5. I've never had a problem with any of them, save some war rifles that I knew were a project when I bought them.
I have a Springfield Mil-Spec, and Ultra-Compact, both purchased used and both warranted by Springfield -- although I've never had a problem with either, not in 20 years.
1911 is an inherently $$$ choice. They're also a long-term investment and a good one is only going to increase in value. I think better to shell out some extra for quality and then have it for decades to come.