After researching a bewildering array of high-capacity SD cards for my
Nikon D40x, I've decided to go with a Transcend 4GB SDHC card.
However, while shopping for them, I've found two different labels on
what appears to be the same card, yet one is significantly cheaper.
For example, Tiger Direct offers this card for $29.99: http://tinyurl.com/yvtyjz

NewEgg.com has what seems to be the same card, but with a different
label, for $62.99: http://tinyurl.com/2mscxu

Both seem to be a 4GB SDHC card with a speed rating of Class 6. The
more expensive card has a 150x on the label, but I'm not sure what
that refers to. Can anyone tell me what the difference between the
two cards is?