That is actually a very good idea, it is something I have pondered myself so maybe that is why I think it is a good idea :)

Of course there are massive challenges associated with international commerce, which means probably only the big dogs (Amazon et al) can tackle this one.

If you just consider exotic foods, the safety issues alone is enough to scare the hell out of any regulator.

One way that this could work would be to perhaps build an Etsy-like network of individual expat/immigrant entrepreneurs who will basically setup shop via your site and be responsible for moving the products.

For instance I have friends who are immigrants and ship products from their home countries and sell them here in the states. So you could set up a service for these people to sell their goods to Americans.