What is the value of War ration book four with stamps inside?

You might be able to get a few dollars for it from someone looking for World War 2 memorabilia. Book 4 was a sort of catch all for things like tires and shoes and not one used often.

A few dollars to the right collector. Everyone that lived in the US was issued ration books, so they are pretty common. Finding one with a lot of stamps left in it is much harder. That would mean that the person didn't use their stamps to buy goods.