I am thinking about selling my laptop to buy a Macbook Air 11". I want to take my laptop to school and the Pro is too heavy for my book bag with all of the books I have to carry. I am not sure what these go for though? Here are the specs: MacBook Pro 13" Released Mid-2010 2.4ghz Intel Core Duo 4GB Ram 128GB SSD It is in perfect condition, I had a case on it since I bought it. I would greatly appreciate honest opinions on how much you think I can sell it for. I don't want to overprice it, but nor do I want to under price it.