NCHBrandon Just bought a Taurus PT145 (3.5" barrel, .45 caliber) for right around $400ish, brand new and stainless steel.

Well there a lot of different guns in that caliber, but for a Semi-Auto Pistol you'll be shooting 9mm Luger bullets. If you want something for self-defense you need a bigger caliber, such as the .45 I mentioned.....it's in your price range and a great gun for the price