Definitely do NOT buy a revolver! While there are plenty of fantastic choices out there for $500 (a good used Dan Wesson 357 Mag comes to mind) you cannot possibly just buy one despite good intentions and an iron will. First you'll pick up a modest low mileage wheel gun like the DW. Then a couple of speed loaders, perhaps upgraded grips and sights. Then a companion piece (say a 6" barrel to compliment the 4"). One weekend you'll notice the S&W Mountain Guns and find yourself drawn to buying not one but three (45Colt, 41Mag, 44Mag). And no one owns one 41Mag; it's either none or a collection so now you're looking at 657 options, out-of-production Redhawks and collector's Dan Wessons. After a long night drinking you buy a Taurus, a mistake you vow to never repeat but somehow you come to like the Judge. And once you've tried the big bores there's no turning back....460 Rowland, 480 Ruger, 454 Casull, 460 Mag, 50 AE, 500 Mag. Soon you're tapping your credit line, maxing your credit cards and dipping into your girlfriends purse 'cause that Lew Horton is calling your name!
Oh, wait, that's me. I'm sure you'll be just fine!