CHAT: Amazon and e-shopping

I have a question aimed mostly at non-US residents:
who of you have bought a book from Amazon or any other
web-based bookstore, and how much have you paid for
shipping and customs? Some time ago I was taking a look
at the offers in Amazon and I thought I could use some
of them, but then it said 'you have to pay this and this
for shipping, plus customs and any other charge your
own government might make you pay'. Those of you who
needed overseas shipping, did you have to pay anything,
or what?

(I know I should go and ask *here*, but finding a
competent and helpful customs official in Argentina is
about as likely as finding a wild kangaroo in Alaska.)

Any help, please?


--Pablo Flores