The cost would be different from each town to it's destination.
5
It depends entirely on the value of the stamps. In 2010, a standard letter currently requires a stamp or stamps to the value of 60c within Australia.
one
i dont know you tell me
For a regular letter, two.
The rate is $2.10 ( Australian) from up to 50 grams via air mail from Australia to the US.
Stamps depend on weight, not distance. You can find much more here: http://www.usps.com
your post office will weigh the letter and tell you the exact amount, they will then sell you the appropriate stamps, put them on your letter and mail it.
how many forever stamps = .94
I successfully mail CDs all the time with 2 stamps.
4 stamps
4 cents was the postage rate for standard items of mail within Australia from February 1966 to September 1967. Beyond that, 4 cent stamps were produced until 1988. There would have been billions of them made.