I have the 100 Years binder and a regular binder from WDW.
As long as they are in stock, you can buy them directly from WDW Merchandise or DL DelivEARS.
WDW Merchandising:
WDW.Mail.Order@disney.com
Phone number: 407-363-6200
You can buy through them anything that is for sale at WDW, EXCEPT Limited Edition pins. And it is better to know what rack pins you want. They seem to be very limited on their searching capabilities, at least from my experience.
They charge a flat shipping fee ($8?) to ship any order under $100. So it's better to buy what you want, as long as it's under $100. Plus -- no Sales Tax!

WDW Attraction Merchandise Mail Order
Open Monday thru Friday 8:30 - 11:45 and 12:30 - 5:00 (eastern)
Disneyland DeliverEARS - 1-800-760-3566
I know some call World of Disney (either coast) directly to get their Disney Club 10% discount off their purchase.