I was casually cruising Cheaper Than Dirt, looking at ammo prices, and found these:
.458 Lott, $168.05, 20 round box
.460 Weatherby Magnum, $165.92, 20 round box
.500 Nitro Express, $207.76, 20 round box
.505 Gibbs, $193.40, 10 round box
YIKES! Glad I am not a big game hunter. CTD even...