That stamp is Scott Number US 2263. It was issued in 1988. It has a value of 20 cents used and 35 cents mint.
If you mean the US stamp, it was issued 1990 and about mint .65c used .20c
That would be Scott number US 2496. A full sheet of these stamps has a catalog value of $44.10.
The 1973-74 US stamp is worth .20c for both mint and used (in excellent shape)
Mint US stamps are worth their face value to use as postage. Dealers usually charge twice face for common US stamps, so you could say its retail values is $0.40, provided it is well centered and still has all its gum.
Barely, probably the face value of the stamp.
The D stamp has a face value of 22 cents and can be used on domestic mail at that value.
15 cents.
Forever
It's a 1969 Haiti stamp worth about .20c US.
value is 25 cents
The F series stamps were issued in 1991. The postage stamp has a face value of 29 cents.