Part of the answer is driven by which matches (and how many) you're going to shoot. The Board matches, ie President's 100, NTI, NTT, and NTIT are less expensive but you supply your own ammo. The CMP Games, ie Garand, Carbine, and '03 Springfield matches include the cost of issued ammo and are less expensive as well (~$45 each). The NRA Nationals are much more expensive (~$250-300 IIRC) and you have to supply your own ammo too. Hotels run between $80-150/ night. Huts or barracks on site are less expensive but go quickly in late April/ early May. Meals are what you choose on or off post. The most expensive (and dangerous) thing is commercial row. dance2
That's a start.
Eagle 1