Used example of the 1954 4 cent Lincoln, Scott number 1036. This is one of the most common US stamps of the 20th century. Billions of copies were printed and used. It's hardly worth a penny.

But some seller on Ebay, through either dishonesty or ignorance, or both, are offering examples of this super common stamp at absurd prices. One person has one up with an opening bid in the thousands of dollars. So, for those who really believe that these stamps are worth $$$, just for these people, I've put a $25 buy-it-now option. Such a bargain - how can you pass it up?