How much is a 1976 two dollar bill with a Plains GA postmark from Jan 20 1977 reading Inauguration Day and a stamp worth?

When the 1976 $2 bills were issued, many people took them over to their local U.S. Post Office to have a cancellation applied to prove that the bill was obtained on the first day of its availability. These souvenirs are quite common, and are not worth much more than ordinary 1976 $2 bills. source: http://taco.com/reb/2bill.html But this is also a piece of Jimmy Carter Presidential Memorabilia. I'm not sure if that makes it worth more or less. I've never met a collector who admitted owning any Carter items other than Billy Beer.