RE: 30-378 or 308 warbird
Hi footballboy5571,
If you're willing to reload (can get started for about $100.) you can cut ammo costs considerably. You will still get "pinched" when you buy the first ammo or brass...but beyond that it wouldn't be much more expensive than the standard magnums. (A little more in powder and probably the cost of premium bullets to insure they hold up...but no where near the cost of factory.)
As for the rifle on a budget...I think Savage chambers for the Lazzeroni cartridge. But no matter how you trim costs...it will always be more than a more common caliber. The price of exclusivity!
Good luck!