I have a Jan 2011 MBA 13 Ultimate. Let's say I wanted to be one of those guys who has to have the newest model. What would be the most economical way for me to upgrade. Would it be wise to sell my 6 month old MBA now and put the money towards the newest one that will likely release in a month or so? I realize I would have to not have an MBA for a period of time to do that. If I were to sell my MBA now, do you have any recommendations on getting the most in return for it...is Ebay a reputable choice for something like this? Thanks.