I have a 2010 MBA in excellent condition but want to upgrade to the rMBP. I'm looking at buying through Amazon or Apple (gov't discount). I also want to trade in my MBA through the same site I purchase from so I can use the money toward my new rMBP. How can I buy a new laptop and trade in my old one at the same time so that I can use the trade in money toward the new purchase. I believe Amazon and Apple make you send them the old laptop before they give you the money (which makes sense); however, my MBA is my only laptop and I can't go without a computer for a week. Any suggestions? I don't want to deal with eBay or Craigslist. The difference in price is not worth the time/headache for me.