The CZ-75B, the Ruger P-95, a refurbished Glock 17, or a used Browning Hi-Power can all be had for under $400, and some for much less. All will probably shoot as well (or better) than you can.
The CZ-75B would be my first choice for all-around shooting, and the Browning Hi-Power for concealed carry (although the difference in the size of the Browning and the CZ is not much.)
I have or have had all of the guns cited above, and now have a CZ-85 Combat. I prefer it to any of the ones cited above, but the Browning's a close second place.