At $2 a sheet for a 50 sheet box, that's $100 + $23 for Priority Flat Rate box.
Here in Japan, the cheapest I can find is Amazon.co.jp, for 7800 yen per 20 sheets (with free Prime shipping). which amounts to like $195 for 50 sheets. Still quite a bit cheaper.
If I can get 2x 50 sheet box, that's $223 for 100 sheets vs. 39,000 yen (~$390), making it MUCH cheaper.