I'm "test driving" a 13" Macbook Air right now -- but who am I kidding, I know I'm gonna keep it. But I'm wondering whether I ought to hang onto my Samsung Chromebook for whatever reason. (Backup field unit? Casual email checker? Foul-weather laptop?) If not, I guess I could try to sell it -- but what could I hope to get for a Chromebook that cost me $299 a year ago?