Hi, I am in need of a computer over the summer, preferably a mac, but would ultimately like either the updated mbp retina or zenbook infinity coming out this fall. I am curious as to how much I would lose if I bought a mba 2013 either used or new, and then sold it around the time one of the previous became available. So basically I am asking how much do you think I will be able to sell a mba for around sept. or oct? Also, which site should I use: amazon, ebay or a different one? Any other tips or help would be greatly appreciated as well.