Firewire express cards?

Question

I've been looking on ebay and in local stores for a Firewire ExpressCard. Why on earth are they priced so differently? Some I've seen on ebay go for $30, some in stores go for $120. Quite honestly, will it make much of a difference on the whole? Apart from the build quality, ofcourse.

Answer 1

http://www.newegg.com/Product/Product.as...

There is one for $44.99.  Probably only $30 because either 1. They got a good deal and want to share it, or 2. It is used.