[bert]

The increase in the postage commodity is a direct indicator of the devaluation of the US$

[Menehune56]

Here's a link with an interesting graph showing inflation adjusted postal rates since 1885. First class stamps actually been more expensive in the past using constant monetary units.

http://stampsmarchingforth.blogspot.com/2011/10/usps-will-increase-first-class-postage.html