RTF?
The Czech CZ pistols can be had cheaper, though I've heard mixed things from them in terms of reliability and quality control. Accuracy is generally well-regarded at least. As a carry piece, if that's something that interests you (or anyone else reading), forget about it. For a range pistol though, you can do worse than the Czech CZ pistols. S&W SDs are Glock clones and they're a bit cheaper, while still being generally quality. They also make the Sigmas. Don't know about the quality of those, but every S&W I've used or heard much about is usually pretty solid. Aside from those, basically the only pistols you're going to get for like ~$400 and under are either pocket pistols, pieces of shit, or both. You could do worse than Hi-Points for something that's like $180, so you could spend the rest of the dosh on ammunition. Problem is, Hi-Points are blocky as shit, a tad unwieldy, and heavy. Definitely not carry guns, like the CZs, except actually worse for carry. Still, they work, and they have a life-time warranty. You just have to pay shipping to get those shits repaired.
I would advise going for either a CZ or S&W for a budget gun.
If you could cough up $550-$600 for a Gen 3/4 Glock, that's a good idea. The 19 I use is damn solid. Only three malfunctions in probably a thousand or so rounds, and that was probably the result of budget ammunition quality control failures (not able to replicate those failures). It's a Gen 4. No problems with the stock grip stippling, running stock everything. Stock sights are decent, although replacing them with some tritium insert sights would be smart. Trigger runs well, mags are reliable, and the three stock 15-round mags run like champs of course.