How much is a Ab Lincoln 4 cent stamp worth?

four cents

Maybe Scott #1036/#1058 - Purple sheet/mint ??? You can purchase one of them mint for about 30 or 40 cents, used for about 15. Scott #1116 - Horizontal Blue Commemorative This would cost you 50 cents...

Not to be a smart-aleck, but the stamp is worth 4 cents...or less. One can buy bulk stamps at online auction sites that include lots of individual and plate blocks of older stamps. These items sell...

These are all still easy to find. You should be able to buy a mint copy or a nice used copy for 20 cents.

Scott US#2171 This stamp was first issued in 1986 as part of the definitive series of Great Americans. It can be purchased online from a dealer for 15 cents used and 25 cents mint. The nominal...