>Does anyone have a good source for them?  I've heard bad things about pricing.

I bought my from Brumley & Associates (http://www.brumleynet.com).

A Silver card is $159.00 from them.  Probably close to the best retail
price you'll find for them (I've heard about people getting them for
cheaper, but somehow those prices never were real when I investigated
them).  They "just work" with the wi driver and the Apple Airport.

--Ken