To anyone outside the US, you can easily add a second US address (or any other country) to your kindle account.
Go to Your Account > Manage Your Kindle (in the Digital Content section) > Country Settings > Enter any US address and click update
You will now have US pricing. You can go ahead and add different addresses in other countries and you can simply switch between them to take advantage of different pricing, because Amazon remembers your previous addresses. The country you have selected has no effect at all on being able to download the book, you can still download from anywhere.
Go to Your Account > Manage Your Kindle (in the Digital Content section) > Country Settings > Enter any US address and click update
You will now have US pricing. You can go ahead and add different addresses in other countries and you can simply switch between them to take advantage of different pricing, because Amazon remembers your previous addresses. The country you have selected has no effect at all on being able to download the book, you can still download from anywhere.