Each day, the store is opening at an unannounced time to offer a limited number of copies of Darkfall to the players. Once their goal for the day is met, the store shuts down immediately and the prospective buyers with empty hands have to go home pouting until the next day. This has lead to some players becoming demoralized while others use their expertise to suggest solutions to Aventurine. It is an odd time on the forums indeed.
Now, we here at Massively understand that finding the Darkfall shop is like finding a unicorn. If you're having trouble finding where the button to go to the shop is even located, it's on the account page after you sign in. After that, however, you're on your own. Good luck though!