Back of the Book stamps are those that are used for special purposes. These include Air Mail stamps, Special Delivery stamps, tax, official, and postage due stamps. In stamp albums and catalogs they are found at the 'back of the book.'
Stock Transfer Stamps are called 'Back of the Book' stamps. That is because they are found at the back of the stamp album or catalog. Consult a catalog that includes them. Scott's Specialized US Catalog includes them.
20 stamps
Revenue stamps are part of a group called "Back of the Book" stamps. They will be found in the 'back of the book' or the back of the catalog for US stamps. The US Specialized catalog will list it, as will most of the other US catalogs. You can usually find a copy at your local library. It will also tell you when it was used and how it was printed among other information.
Although there are rare stamps, in general WWII food ration stamps in a book of stamps (with some missing) are worth $2 to $5. An absolutely new book of stamps (unsigned) might be worth $10 or more. A book of stamps signed by someone famous would, of course, be worth even more. Loose stamps (not in a book) are generally worthless - a few pennies, if that.
No they will not buy back stamps
20 in a book, 100 in a roll (assuming you are not talking about a collectors book of stamps).
The average cost of a plain book of stamps is usually around 14-15 dollars. For a half book of stamps the cost normally ranges from 5-8 dollars.
No, you can not resell your stamps back to the post office.
eBay
Yes, they will exchange damaged stamps for similar stamps. They will not give you back you money.
{| |- | Over 4100 US regular postage stamps have been issued. That doesn't count all the minor variations. And that doesn't include Air Mail, Special Delivery and other back of the book issues. |}
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