Ang -
I tried to like the PX series of Beretta pistols but they just don't seem to fit my hand right. Yours may be larger and have a more comfortable grip. I also found the safety too small and stiff for my liking.
For a full-size 9mm, you can buy any of the single-stack S&W 9mm pistols for around $400 in excellent condtion. My favorites are the 1st two generations - the Model 39-2 and the 439 (2nd generation). These are 4-inch "service" pistols, but they conceal rather well due to the narrow profile.
S&W Model 39-2, 9mm 8+1 capacity
On a lark, I picked up a well carried but lightly used S&W 3914NL. This is the blue version of their 3913 Ladysmith pistol, with nightsights. While trimmer than the older 39-2, and a 3.5" barrel and it will use the 39-2 magazines (even if they poke out a bit). Capacity is still 8+1.
This has become a favorite summer carry gun due to its light weight, bobbed hammer and excellent accuracy. Because the finish wasn't great on this one, I picked it up for under $250 - a major score for an excellent pistol.
The CZ-75B series gets plenty of rave reviews from owners and they are good guns. I can never quite reach the safety though. But their new P-01 pistol has a decocker lever mounted close to the thumb's position which is much easier to reach. I've not yet fired one, but this is on my short list of 9mm's.
CZ P-01 Pistol
Even though it is a .45ACP and ammo is more expensive, the almost ideal CCW pistol (IMO) is Colt's Defender. This is out of your immediate price range, but should be given consideration. It's one of the few 3-inch .45's that works well. It's pointing characteristics (with the Hogue grips) are excellent and its business end is a huge gaping hole.
Colt's 1911 Defender Model .45 ACP
There is nothing wrong with the 9mm when used properly and you make good hits on your target. Good hits, however, are center-of-mass (COM) into vital organs or the brain/spine (CNS). With premium JHP ammo, the 9mm is quite adequate for self-defense.
However, there is also a difference at the "business end". Despite the small size difference on paper (0.097") that does translate
visually to a much larger hole. Any gun pointed at you is intimidating, but the bigger the hole the more worrisome it looks.
Kimber .45 ACP (L) vs. Colt 9mm Combat Commander (R)