Pennies (note the spelling; cents, actually) have been struck for hundreds of years at 3 different mints, so it's not possible to say without having more details.
First, you need to know the coins' dates. Different numbers of coins were struck each year so some are much rarer than others.
Second, you need to know where they were minted. Cents without mint marks come from Philadelphia, while those with an "S" come from San Francisco and "D"s from Denver. Again, different mint marks have different rarities.
Finally you need to know how worn each coin is, because coins that are less worn are worth more than ones in worse shape even though they have to same date and mint mark.
There are a number of sites listing values. Some pages that I've found to be pretty accurate are:
Indian Head: http://www.numismedia.com/fmv/prices/indcnt/pricesgd.shtml
Lincoln 1909-33: http://www.numismedia.com/fmv/prices/lnccnt/pricesgd.shtml
Lincoln 1934-present: http://www.numismedia.com/fmv/prices/lnccntmo/pricesgd.shtml
There is a lot of variety in asking about a 'two cent stamp.' You will have to determine a lot more about it to determine value. Consult a postage stamp catalog, usually available at your local library for exact identification and catalog values. Most used US postage stamps are worth 15 or 20 cents, the minimum amount required to catalog and stock the stamps. Unused will always be worth at least their face value. Special cancellations and different values are likely to be worth more. If it is truly an old stamp, it could range in value to a couple of dollars. If it is a really rare variety, it could be worth much more!
One cent, it's not old enough to be worth any more.
First of all you have to be sure it is 'rare.' There are hundreds of six cent stamps that have been issued, some well over 100 years old. They could be worth anything from 6 cents for postage if unused to hundreds of thousands of dollars. The first US 6 cent stamp #115 was issued in 1869 and the mint version can be purchased for $1,750. There is a 1909 #362 that is worth $18,000 if used on envelope.
I have found some old original food stamps that I took back some 25-30 years ago at my family grocery store. I have been trying to find out how much these are worth since the Fed. gov.burned all the stamps that were redeemed. patribelin@gmail.com
Around one us cent.
All U.S. stamps since the Civil War can still be used to mail letters and packages. So a 4 cent stamp is worth 4 cents today. If the stamp is old you can check in the catalogs to determine collector value. Few stamps issued since 1950 have significant collector value.
It depends how old it is, if it was 10 years equals 5 pounds in our country.
one cent
I have a cigar box full of Chesterfield Stamps. Are still valid, or are they worth something? My guess is they are at least 20 years old.
Without more information on mint marks and condition, we can only say it is worth at least 1 cent.
The US Post Office continues to make 4 cent stamps today. 4 cent stamps were issued to cover the first class rate of postage from 8/1/58 to 1/6/63.
Yes. All small values 1,2,3,4 and 5 cents are readily available at the Post Office. I am not sure about random values like 11 or 24, but you can put multiple lower denomination stamps if needed.