Will need more information. You can consult a stamp catalogue at your local library to identify the year and condition of the item with an estimated value for it.
Post cards are listed as 'back of the book' items in the country of origin.
They are probably worth 9 cents.
3 cents
$5,000,000
No, it is only worth 32 cents.
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.
That would be Scott Number US 1755. A full sheet of these stamps has a catalog value of $40.00.
That would be Scott number US 1745-8. A full sheet of these stamps has a catalog value of $21.00.
In the US you can buy two 10- cent stamps, four 5-cent stamps. five 4-cent stamps, ten 2-cent stamps or twenty 1-cent stamps for 20 cents at most post office windows.
That would be Scott number US 2496. A full sheet of these stamps has a catalog value of $44.10.
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!
The H stamp has a value of 33 cents toward postage. The H Make-up stamps are worth 1 cent. Both are valid for postage within the US at that value.
The US ten cent Christmas stamps have minimal value. But if it isn't US, what country issued it, whether they are used or mint, and their condition all affect value. Consult a stamp catalog for the country in question and identify the stamp. It will also assist you in finding the value.
Yes it is still valid for 1 cent worth of postage on US mail for a domestic location.
Air mail stamps are good for ordinary postage- your stamp is still worth 7 cents if unused.
That is Scott number US 1548. It has a value of 60 cents mint and minimal 15 cent used.