You're talking about shipping from the US to an overseas location, correct? That's expensive. When it comes to a relatively large, heavy box of frozen food that you need to arrive as fast as possible, it is fantastically expensive. A box one cubic foot in size would be over $200 USD to ship via UPS. When you take into account the size of the dry ice + cardboard and several inches of foam insulation (cooler and packing peanuts, usually) you don't have much room for burritos. Jump up to a 16x16x16 box, and you're over $400 USD, and that's only if you don't go over 30 pounds.

So yeah, basically, I don't think you could fit enough burritos in a box to make it worth the shipping costs. By my rough why-am-I-bored-enough-to-do-this-math calculation, you'd have to fit over 50 burritos in the 12x12x12 box before breaking even. Double that for a 16x16x16 box. And then you're over the weight limit for that size box which makes shipping even more expensive, blah blah blah. Even if you somehow manage to save yourself some cash, it probably won't be much.

Bottom line: not worth it. Unless my original US -> overseas assumption was incorrect, in which case all bets are off.