The used market should be considered. It might allow you to get a higher quality pistol at a reasonable price. Nearly half of my pistols were purchsed used. The Sig Pro is a polymer pistol and priced much lower than most Sig pistols. They are a little lighter and hold up quite well. If you find one used, that might be an option. A few years ago Sig P6 pistols were selling quite cheap. Maybe you can find one still for a reasonable price. I have put thousands of rounds down range in mine. Kel-tec and High Point pistols are not ones I normally would pick. 9 mm pistols are probably the best way to go for self defense on a budget. You can get ammo at Walmart for a reasonable price so you can practice. You might even consider a .22 pistol for one of your two pistols. It is easier to learn the basics with a .22 and ammo is cheaper than even a 9 mm.
As already mentioned .45 is a great caliber if you reload. Otherwise you will find you can't shoot it much since .45 ammo is fairly high priced. The same goes even with .38 Special/.357 revolvers. They once were cheap to buy ammo for but that was a long time ago.
Getting into reloading should be looked at as starting another hobby. Depending on your available time and space you may or may not want to try it. You can start out with a simple single stage press for a reasonable amount of money to load small quantities at a time. You will find reloading tends to suck up your available funds pretty fast. You do get to shoot more but you really never spend less than you able to do before reloading. I know I tend to hate that draining of my account everytime I have to buy components to keep reloading my ammo. I do buy in bulk so it takes a big chunk of my hobby money for every order. Bulk buying does get me lower pricing.
A good holster and belt really are needed if you are going to carry a pistol concealed. It makes a world of difference how well you can conceal a pistol and how the weight is felt.