In defense of the original poster, the economic value of a specialty area such as these "premium stamps" and their social and historic interest are often unrelated. Nor does cost of acquisition necessarily have a relation to ease of acquisition. These cinderellas shed an interesting light on corporate attempts to win and keep customers. I don't collect these, but I have a few which have landed in a stock book over the years.

Here are two of the booklets to accumulate the stamps:

There are 1560 stamps affixed inside the Community Gift Bond Stamp booklet, and I note that one stamp position in the MV series has a security number 2 digits lower than its surrounding stamps, thus 720 instead of 722 - the center stamp in the block shown.

Edit, here are a few more...
