I agree there are lot's of good guns out there in the 500 dollar range, and nothing wrong with finding a "used" good gun in that range either, some of the best deals might be used guns if you look around.
Reliability is a must, you can make that happen either at the smith or maybe yourself if your into it. Cast vs. forged vs XXX....there will always be lots to read on that, you just have to go with what you think. I bought a new mil-spec Springer in 2002 for 400 bucks, I ordered around 200 bucks or so of small parts I wanted from Brown, EGW, Smith & Alexander, etc...after about 5000 rounds or so went through it, I decided this pistol does not have to take a backseat to any other brand as far as reliability, and I like the forged frame and slide. It would however take a backseat far as shooting tiny groups, I decided I was not going to put any more money into it for a long time, the role of this pistol is not shooting tiny groups, it only has to go off, eject, and self load all the time with no exceptions. 1" groups at 25 yds, NOPE...more like 3" depending on ammo with my old eyes and using a rest...but you can pop a gallon milk jug at 50 yrds if you aim careful every time, and groups are real small at 12 yds which is what I need for this 1911. When I see a Wilson I drool, a Les Baer makes me break out in a sweat, sure would like something like that, someday if funds allow maybe. I have made this 1911 reliable for under 600 bucks, if I buy another one I will by it used, that would have saved me some bucks too. Main thing is whatever you can afford, shoot it enough so you can tell if it's reliable and count on it, that is all that matters no matter what you spend, because big brand names and the little names are going back to customer service a lot these days...stuff happens with all of them sometimes. You bet your life on something you have tested yourself, not a brand name.
You still could have something happen after all that too...cause sometimes stuff happens.