New guns....I think the cz-75b at right around $400-$500 new is a great deal, seeing as you are getting a proven, high quality, all steel handgun at around the same price as most of its clones. I paid $450 for mine and was amazed at what I got for the money.
The newer auto loaders in general are getting pretty bargain-y considering what you get for $350-$500 from ruger, s&w, Springfield, glock, and all the Turkish and Philippine guns.
Go below $350 though, and you are better off shopping used IMO.
Used, s&w M10's are still pretty common and can be had for sub $300. I bought a hb m10 last year for $275 with holster wear, and incredibly, a lovely m10 pencil barrel that is almost unmarred except for a faint turn line not even through the bluing....for $205. I keep seeing bobbed dao m64's for sale for $275 online.
I have bought two zasteva ez9's for less than $250 each the last few years, and those were incredible handguns for the money, and dirt cheap because nobody knows what they are, it seems.
And as a closer, hi point. Because it will go bang for $100 unless you are one of the unlucky few that got a dead hi point.