Originally Posted by Shintsu
Well, I hadn't really considered anything "rated" below the 9mm in power and it was my impression that .38 Caliber, .380, .32 and such were rather low power
Ballistically, 9mm and 38sp are pretty even in terms of performance. 380acp is about the same diameter, but 20% lighter and pretty slow. 32acp is only for micro guns.
9mm is about the easiest and most affordable defense platform to learn on. It is a very adequate defense choice IMO. I always carry either 9mm or 45acp. I'm pretty good with a 45acp. But I'm better and faster with 9mm, so that's what I usually carry.
It sounds to me like you want a 9mm compact (not subcompact), and just don't know it yet. Polymer will give you the most simple, versatile, and reliable (new) gun for your $500 price point. Glock is fine. So are FN, SA XD, S&W M&P, Ruger SR9, Beretta PX4, etc. And I say this as someone who doesn't prefer poly guns.
My advice is to buy a versatile 9mm that can serve you well at home and the range, as well as being just small enough to carry (Glock19, XD9c, SR9c). Also do yourself a favor and look into Bersa. And if you've got the bug, you'll eventually add larger calibers and/or smaller carry-specific guns.