Depends on the cartridge. For rifle unless you have a 223 or a 308 (there might be a few other military rounds) you will find it prohibitively expensive to shoot a lot or get decent quality military ammo. If you shoot the big stuff you will almost have to reload - the ammo is very expensive and all the factory stuff is full power.
For handguns its a little different. I do not reload 9mm or 40 but I reload some 357 Sig because that is more expensive. Reloading is a toss up for most defensive handgun rounds (9mm, 45, etc) - it depends what your time is worth and how much you shoot. Again, for the big bores (454, etc) many people reload due to cost and the ability to shoot reduced loads.
If you buy a decent press, scale, measure, etc in the beginning the cost to add a cartridge is very low - you just need the dies and a shell holder.
For handguns its a little different. I do not reload 9mm or 40 but I reload some 357 Sig because that is more expensive. Reloading is a toss up for most defensive handgun rounds (9mm, 45, etc) - it depends what your time is worth and how much you shoot. Again, for the big bores (454, etc) many people reload due to cost and the ability to shoot reduced loads.
If you buy a decent press, scale, measure, etc in the beginning the cost to add a cartridge is very low - you just need the dies and a shell holder.