Get your stuff from bhphoto.com, they are a little more expensive but trustworthy, dependable, and excellent customer service. If you google us1photo you will find several dissatisfied consumers and issues w/ buying from them. Not to mention the better business bureau has rated/graded us1photo with an F (http://www.bbb.org/new-jersey/business-rev…den-nj-27003943).
There is no difference in the memory cards. Its just a scam to get you to buy from them at their high prices.