Hmmm, something similar just happened to me yesterday. I bought a set of 2 4GB SDHC cards and the pricetag had them at 30,99$. Apparently, I paid 20$ more!
I still have my receipt luckily, so I will show them! D:
Oh, I bought them at FutureShop by the way.
Random game thought :
Why is Bionic Commando Rearmed 2 getting so much hate? We finally get a real game and they're not even satisfied... I'm starting to hate the gaming community so f****** much...