Maybe it's because I really only buy 5.56 and 7.62, but that doesn't match my experience. My local WM sells the 1000 round box of 5.56 (when they have it) for $499. CTD sells it for $399 and charges $30 shipping.

Same for spam cans of 7.62x54R - I've never seen them for sale anywhere but I can buy them from CTD for $90 shipping all day long.

If there's a better way/place to buy ammo then please share...