If 30-06 ammo could be bought or re-loaded for about $.25/round, without a doubt an M-1 Garand. In second place would be a civilian M-14 or FN-FAL. This ammo is also too expensive.
My wife and I visited the Bastogne (101st Airborne's E and F) WW2 foxholes and some skirmish sites and descriptions, known only by veterans and our personal tour guide.