Wow! NGIB was stuck at work earlier and would have shat a sailboat to get this topic while he was stranded.
A $600 to $700 1911 is do able, but he is going to be going into a platform that he may WANT
to do some modifications to down the road.
I think used is the best bet for a quality piece in this price range. You are going to get more weapon for the price and you might get a couple of "bells or whistles" for the same price.
What to look for:
The "Dummy Scratch": It's a 12:00 to 6:00 running scratch in the frame where the slide release was put back in the weapon but rotating it from 6 to 12 and pushing in on the stop onto the frame. Everyone who is a first time owner, *raising hand* has atleast tried this and might have left the scar. Most have.
How is the slide, especially around the running rails from the frame? Is it well worn, or is it barely broke in?
If you can look at the barrel, with it removed from the weapon, shine a light down or hold it up to light and see if the lands and grooves are worn/dirty/not clean and crisp.
Slide release: Is the top, where your thumb goes, well worn or is it fresh and new and still gives that "new pistol" bite when you thumb it?
Grasp the slide, while it is closed, and wiggle it. Is it a tight slide to frame fit, or is it loose and it has some slop. A nice, tight, slide to frame fit is important, but you don't want it so tight that you have to fight to get it to rack open with the thumb/forefinger over the top of the slide quick check.
Are the grips worn or are they fresh and clean?
Sights: I don't believe he needs adjustable ones, and a lot of factory models come with them. There is no need to have them on a carry pistol, so don't spend the extra money on them.
The more wear on any of these parts, the more it has been used and possibly abused.
More to follow after I give this some thought...