Well, it would certainly be possible to bring the 8gb to $149. However, its not the price of the phone itself that would turn of the Costco crowd--even at $199. (There are $1000 TV's at Costco). It's that it comes with the expensive, required data plan.
a friend told me a rep at Costco said after the new year they will have a bunch of 8gbs at discount. Didn't say $149 but did say it will be discounted from retail... I assume $175 because that's what I got through my FAN.