To access the shop, you need to wait until the two obelisks on either side of the portal have been lit to the top. There are five lights, and it takes about 30 minutes for all five to be lit. Switching realms may bring you to one that's further along in the cycle.
Once you teleport to the top, you must enter the shop either three or five times to earn the Secret Shopper badge. (I've read that it's five, but it only took me three.)
I teleported down and up over and over to get the badge; you may be able to simply enter and exit the shop.
--Akylax 16:59, July 1, 2010 (UTC)Akylax
It appears that there is a visual timer on the obelisk the red sticks hyroglyph lights up all the way when the shop opens. I just found that out a few days ago. Favorite character Zachary Nightdreamer, lvl 22 krokatopia oasis, adept necromancer. Highest character, Aaron Nightdreamer, lvl 31, magus thaumaturge, regents square.