I have not looked at Posner's listings in some time and am more than a little shocked.
There are a number of listings that are overpriced and over described to say the least. I picked one at random.
Here is a US Scott 245 described as "Fresh":


The stamp is priced at 80% of catalog and makes zero mention of the large crease running across it nor the multiple thins, the largest of which, in the UR corner, can be seen from the front.
https://www.ebay.com/itm/US-SCOTT-2...383989375570