If you have no reloading equipment it can be quite an expense to get started.
You need:
a press - this can be used for all calibers and are used to de-prime, resize, prime and seat bullets
a scale - to weigh powder
dies - these are caliber specific
calipers - to measure case and loaded cartridge length
trimmer - a way to trim cases when they get too long
cases/bullets/powder/primers - selection for the caliber/cartridge you want to reload
it is also nice to have:
a tumbler - to clean fired cases
chronograph - to give you an idea of bullet speed
primer pocket cleaner
The above is going to cost a minimum $300 new, probably closer to $500.
Currently I load for the .338 Winchester magnum; premium bullets (Nosler/Barnes) are about $1 to $1.50 , cases $.75, primers $.03, powder $.25.
I reuse cases 5 times so this averages $1.50 to $2.00 per round, the last I checked factory ammo was $2 to $3 per round.
The savings by reloading is offset by a couple things:
Initial cost of the equipment above.
Reloaders tend to shoot more; developing loads, trying new components and so on.
If you are doing a high volume of shooting, which is doubtful with .300WM and .338WM, reloading will pay for itself especially in competitive handgun, shotgun and rifle or varmint hunting.
If you use the above rifles just to hunt it is doubtful you would go through 50 rounds in 10 years(say $150) , the cost of which barely offsets the cost of components and dies (say $125) never mind the equipment.
All that being said I enjoy reloading and the choices it allows me.
Dan