One thought, if cost is a big factor: it won't take long to spend 700 bucks on ammo at today's (retail) prices IF YOU PRACTICE REGULARLY, which you should do, if you plan on Carrying. At 15 bucks a box, 2 boxes a month, in a little over 2 years, there's your 700 bucks.
Steps to Take To mitigate ammo cost:
1)choose a common caliber- .38 spec, 9mm, .45 ACP, and avoid odd ones- .32 H&R Mag, .357 Sig, .45 GAP....
2)learn to handload, and choose a gun/cartridge platform that is easy to load for- .38 or .357 revolver, or a .45 ACP 1911, and avoid those that have "issues" with handloads - high pressure catridges like .40 S&W, guns that have funky octagonal rifling like Glocks .....
3) Buy PRACTICE ammo (or components, if you choose to "roll yer own") in bulk,
Of the guns mentioned above, I would recommend the SP101 in .357 Mag for a first carry gun- Inexpensive (NOT Cheap!),Tough, small, with power to spare (with premium Personal Defense Loads) and you can reload your own .38 Specials to practice with. You will have a couple hundred bucks left over to pay for such things as a Good Concealed Carry Class, a GOOD belt and Holster, a nifty handloading set-up, or a couple years worth of WIN White Box....
My first pistol was a 5" steel framed 1911a1 Clone. It only took me one hot summer to decide that it was just to heavy (particularly so when loaded, with a spare mag) and big to Carry in light summer clothes.