It varies by size, destination, weight and type of delivery required
It will cost you 98 cents for an ordinary up to 1-ounce letter.
if you get a certain mail company you can ship it for free if it fits it ships
First-Class Mail International Letter $1.05 (as of August 2012, but it increases every year or so).
That depends on where you are mailing the letter from.
That will depend on where in the world you are sending it from, which you have not stated. Rates differ in each country and rates change all the time. Your local post office will give you rates at the current time.
As of this writing, a 4-ounce letter sent from the U.S. to the U.K. will cost $4.60, or more if you choose Priority or Express Mail service.
found this page useful http://www.royalmail.com/delivery/mail-advice/channel-islands-or-isle-man
The cost is 98 cents to mail an ordinary, up to one-ounce, first-class letter to Europe from the US.
Probably less than you think, just mailed a first class letter to Russia, from the UK for £1.67, which is like, 3$?
Letters sent by the royal mail with the Airmail service ( not you will need a special air mail envelope, these should be available from your local post office) will cost 56p to send to a destination outside of Europe. If the letter is heavier than 10g it may cost slightly more.
50 pence.
Sending a card to the UK will cost much more than sending one to Canada. The cost of sending a card to the UK would be about 5 to 7 dollars. Sending one to Canada will cost about 2 dollars.