Lets take the stamps from the early 1970's. At face value they are 6c, 8c, &10c and so-on. However, for the catalog values, for every grade of each stamp, it is valued at $.25. Typically there is some difference between Mint VF and Used VG. How can they all be the same? They weren't in the 2012 release.
For instance, here is 2012 of US 1409
And here is the same with 2014 Values.
Notice the different values for the grades? Did Scott really print a catalog showing all the same values for almost every stamp? Mint or Used???
Robert