Ireland versus UK versus US prices (Celestron)

Its not like an american tourist here who can buy stuff tax free, that wont work for us in the US.
The price you see on an american site is the price you'll pay.
You'll pay import duty of 21% on a parcel if the value is over 175E on entering the country.

BUT, I've heard that if the item is a gift then the tax is different, I donk know the exact details, does anyone?

Second, if I pay the US tax, does the 21% IRL VAT go away?

Third - if the answer to the above is that I don't pay US tax but pay IRL VAT, then is this on the goods only or do I have to pay VAT on the shipping, insurance etc?

Fourth - I assume that the import duty (4.2%) is due only on the value of the goods.

Last time I imported something from the US it worked like this;

4.2% customs duty added to TOTAL value (goods + shipping)
21% VAT added to the this total (including the 4.2% duty) - Tax on tax, I know... :roll:

I would be worth checking, since the last time I imported something was about a year ago, and the rules might have changed since then.