buying from amazon.com?

hi,
just wondering if anyone here know's what's its like to buy from amazon in america. Mainly the import duty fees and charges i would like to know about.

there's this item,"celestron eyepiece kit"(that i need for my telescope), which i was going to buy from amazon.co.uk that cost around 152 pounds,(around 182 euro when shipped to ireland, with free delivery). But from amazon.com it cost 110 us dollars, which is around 80 euro, but i get charged at 137 euro when am at the checkout, it say that i got to paid shipping and handling and also this import fees and so the total is boosted up too 137 euro at the checkout.

i would like to know must i pay more charges when it arrive's in ireland, like must i pay more import fees or pay ,An Post, more extra charges??,to have it delivered to me.
i really dont know, and dont want to be surprised with more charges as i never bought from amazon.com before.

all help is welcome, thanks