Why is the Sheldon grading scale through 70?

savoyspecial

There must be a reason...

Staircoins

A good explanation can be found here.

In short, Dr. Sheldon felt that a Perfect Uncirculated Large Cent was worth 70 times the value of the same type in Basal State.

ricko

I hope you did not expect some logical, scientific explanation.... Goes along the same lines as why people prefer environmentally damaged coins as opposed to as minted condition. Cheers, RickO