You will need to consult the catalogs and do some research. There are lots of stamps issued and they vary in value from almost nothing to some nice values.
Most libraries will have a copy of Scott's Postage Stamp Catalog of the World. First of all, you have to identify the specific stamp or card. That in itself can be a daunting task, but most of the catalogs are well illustrated with lots of information. Once you know what item you have, the catalog will provide a set of prices that can be used to estimate value.
The basic US postage rate in 1930 was 2 cents.
Postage in 1930 was was 2 cents for a First Class letter in the US. It went up to 3 cents in July 1932. A postcard could be mailed for 1 cent.
The cost of a First Class US postage stamp in 1938 was 3 cents. It was raised from 2 cents in February of 1919. It stayed at that price until August of 1958.
A first class stamp in 1930 was 2 cents. It didn't change until July of 1932 when it went up to 3 cents. That covered the first ounce of postage on a letter.
The cost for the first ounce of First Class US postage stamp in 1933 was 3 cents. It was raised from 2 cents in February of 1932. It remained at that price until January 1952.
The cost of a First Class US postage stamp in 1928 was 2 cents. It was lowered from 3 cents after World War 1. It stayed at that price until July 1932 when it went back to 3 cents.
3 cents
two cents
The cost of postal stamps are $0.28
How much is postage stamps in 2012
The cost for postage in 2005 was 37 cents.
The prices of stamps changes quite consistently over the past few years. In order to stay updated, I would visit the USPS website to see current prices for postage stamps.
42
they cost $0.49
500 first class stamps would cost: Well it depends where you get them from!!! :)
18.5
What is the current cost of a stamp on a first class letter under an ounce mailed in the US? <><><> 44 cents
$8.80
37 cents
$44.oo for 100 stamps at $.44 each