I live in rural Japan in a famous tea growing area. Many of my neighbours are tea growers. They are desperate for ways to export their tea cheaply. I briefly looked into helping them out, but shipping looked impossible. They will sell me 100g of first cut shincha for $3-5 (in vacuum packed foil packages even!). But shipping? It will raise the price 5-10x. I bet the vast majority of his price is shipping :-(
The way to ship internationally is by slow boat. It's super cheap. What you want to do is ship by the palette (or better by the container) and then have someone on the other side forward it on with local shipping. But that takes both volume and cooperation of another entity.
For a small 1-2 person operation, it's infeasible.