May I ask how much you sold it for?
Did you wind up getting what you wanted for your MBA on Craigslist? I just lowered the price of my 2013 13" base MBA to $900 and still no hits. Even if I sell for the $900, it's still over a $200 premium for me to keep the rMBP. For me, comparing those two models, everything is the same aside from the screen. Worth $200 for the admittedly awesome retina display (despite some lag)? That's where I am stuck.