You can buy from outside the US. It's simply priced in US$.
In fact they not long ago added a map for publishers showing where purchase are.
I've also bought in many random currencies off ebay. The Amazon site for Ireland only lists UK Sterling price, despite Ireland split from Sterling before the Euro and before Amazon even existed. I don't use Amazon's currency exchange at checkout either as it can be a worse rate than my normal payment methods.
One wonders has Amazon realised Ireland left UK in 1922 and Sterling about 1987?
I've also bought from Amazon Germany in our Euros, and from Amazon USA in US$.
Obviously Paypal, IBAN, Credit cards, Debit cards and Amazon don't do the same exchange rate as shown here:
https://www.xe.com/currencycharts/?f...to=EUR&view=1Y
Despite Amazon generally having about 90% of the eBook market world wide, only about 66% of our sales are with them. About 1/3rd via Smashwords including those they distribute to. We've had Apple, Barnes & Noble, Tolino and Kobo sales via Smashwords.
Also the Amazon search is terrible compared to Smashwords. Flooded with Promoted, Adverts and unrelated authors. If searching paper books, you get books that you find won't ship, but only if you already clicked and went to checkout.