$12.50
US postage stamps do not expire -- they are always worth face value as postage.
That would be Scott Number US 3561-3610. A complete sheet has a catalog value of $36.75
What is the value of a sheet of Appollo 8 stamps?
"A " stamps are the same as 15-cent stamps.
In all honesty, you best value would be to use them for postage. A dealer is not likely to even give you face value.
Flag stamps were 42 cents face value, they were supposed to be forever stamps, postage never to increase from that 42 cents, but that flew out the window real fast.
Face value for postage remains valid until the government de-values them. In the US, stamps issued since 1865 are still valid for postage. The value to a collector varies based on supply and demand.
It may have value if you can find someone to buy it from you. A postage stamp has value, but not anything that you can demand. You can't hand one to a clerk in a store and they have to take it.
Ordinary stamps were 3 cents each in 1916 .
The F series stamps were issued in 1991. The postage stamp has a face value of 29 cents.
15 cents.