A single stamp is seldom worth much. But put it together with hundreds of others, and batch them in half kilo lots and they can be sold to collectors as modern postage in 10/20/30 dollars lots.
Aproximately New .80 Used .40
I called a collector and they said it will not be worth anything except 1 cent.
A stamp is worth more unused
Your stamp is not rare and is not worth anything. Most German stamps of this era are worth far more if they are used, and the cancellation will ultimately determine the value.
In used condition it is not worth anything. In mint condition it is probably worth 2 times the face value.
It will depend on many factors. Many common single stamps are not worth dealing with. However, depending on what country issued it, whether they are used or mint, and their condition, they could have some value. Consult a stamp catalog for the country in question and identify the stamp. It will also assist you in finding the value.
I am not sure it is worth anything as of now
A used stamp is seldom worth more than a mint stamp. However, that can vary considerably. The stamps of some countries, such as Tonga, are worth more used then mint. And a used stamp on an envelope could be worth a great deal depending on the cancellation and other factors.
If you mean the US stamp, it was issued 1990 and about mint .65c used .20c
There are too many variables to provide an answer here. Is the stamp used or mint? Is it US or another country? How old is it? The stamp could have been issued a month ago or 170 years ago. Is it in good condition or ripped and thin? Consult a good stamp catalog to learn how to identify the stamp and to understand how they are valued.
A 28 cent stamp that is unused can always be used as 28 cents worth of postage. If it is used, it probably has a minimal purchase price of fifteen cents from a dealer.
There is no 1881 Roosevelt stamp. The earliest stamp issued with a Roosevelt, Teddy, was in 1922. Scott number 557 is worth 45 cents catalog used and about $30 in mint condition.