It is best to take it to a Post Office. Postage can depend on the weight but also on the size and thickness of the envelope, the destination, what is inside, etc.
As an example, though, a rectangular envelope (standard letter) with paper in it only, with stamps, that weighs 3 ounces, sent from Long Island NY to Saint George UT on January 29, 2016 is quoted on the USPS site at 93 cents. You can try out other scenarios at postcalc.usps.com.
A 1.25 ounce letter rounds up to 2 ounces, which in 2016 costs 71 cents to mail First Class.
It cost 15 cents to mail a first class mail a letter in 1981. During the 1920s, it only cost 2 cents to mail the same letter.
You can get Picture Mail with a data plan for $15/month.
15 cents
15 cents
Depends all on the weight.
The cost of a post card was 15 cents in 1990. It want up to 19 cents in 1991. Prior to that the 15 cent rate was in effect for 3 years.
it cost about 15
15$
15$
15 cents 15 cents
It can cost as little as $15 a bottle.
$1.15