Ah, I just saw this, although I wrote a (much comprehensive) reply here: https://news.ycombinator.com/item?id=45097345

The full payment that requires pro-rates is even worse. They expect you to pay it fully back. (ie. with the deducted taxes included!)

I bet it is possible to profit from a such scheme if Amazon is able to declare that as a reversed-transaction (similar to VAT-refunds) at the end of the fiscal year.