Best place to buy Ariport card

you can 't get one at bestbuy. The fastest place would be an apple store or compusa or other appel retailer but you will pay tax. I suggest you check ebay. I have a regualr airprot card that i got for $60 used on ebay when they were 99 retail and it works very well. As for fastest other places online i'm sure some ppl will have good suggestions.

Cheap Airport

I have been looking for cheap airport cards and have found that http://www.smalldog.com and http://www.macmall.com often have not just good prices, but also open box items that are even cheaper.

Gid

fry's or compusa might have them, your best bet is online apple store or apple retail stores or an authorized reseller like macmall, macwarehouse, etc.
also like kwyjibo said take a look on ebay.
or maybe someone here has an airport card to sell, ckeck the for sale forums.

if you need it real fast, then i would just go to compusa. theres probably one in chicago.