You'll never outshoot a bone stock CZ75.

Or, put another way, by the time you do, you will have spent several times the gun's value in ammo.

Think of it this way: Say you can get 9mm reliably for 16cpr. A CZ75 costs somewhere around $600 now. 600/0.16 is 3750 rounds to equal the same cost as the gun. You will have to shoot at least 10 times that to wear out a 75. Buy like 4 CZ's and store 3 of them in a tub full of motor oil, somewhere you don't forget about them. When one breaks in like 20 years, throw it away and grab the next one.

Point being: if you get even a decent gun, nothing fancy, ammo is going to be a MUCH larger factor in the cost equation here, pretty much no matter what you get.