1
I mail my letters with 5 cent stamps from the 60's.
The number of stamps is irrelevant. The cost is dictated by the weight of the letter and the method by which it is transported.
it will cost $8.50
it depends. if you want to send it signed post you will get two stamps if not normally one stamp.
1 first class stamp
1 stamp! unless its a big letter
States do not issue postage stamps. The U.S. Postal Service is an agency that operates in the service of the national government, just like the currency (money).
About $0.50
One first class stamp is all that's needed.
Albany, the capital of New York, is much closer to Massachusetts than it is to New Jersey.
Depends what you mean by "space left" in New Jersey.