I have a 12" PB, 1Ghz, 768mb RAM, 40gb HD with some cosmetic damage (dents) and a perfect screen. I also have a 17" PB, 1.33Ghz, 1.76gb RAM, and NO HD with no cosmetic damage and a perfect screen. The batteries on both are about shot and only last 30 mins or so. And I don't have the original powerbrick, I use an iGo charger. I want to sell one to put towards an MBA but I want to keep one as well. Which is more valuable? Also, would replacing the HD on the 17" bump up the value a ton? or would it basically add the cost of the HD to the selling price?