The cost of everything is going up lately. That includes now PDF products from Paizo. Head through to see how much these prices are changing. You have until November 1st to keep getting the files at their current price.
From the article:
For many years, Paizo has largely set PDF pricing as a percent of the full print MSRP. While this process worked well early on, the rise of digital goods and expressions has matured, and the exceptions made for certain categories to be priced higher or lower has somewhat scrambled the logic used to build those systems.
Effective October 26 for new releases and November 1 for all other PDFs (including jpegs for some maps and card products), Paizo will be changing prices in the following categories. You’ll probably find exceptions for some products as well, but this guide covers most cases.