Basically, I need a macbook for school. But I can't afford a brand new one. So I'm getting one off eBay. My question is should I get the 13" air from 2011 or 2014. The 2011 has a better CPU, Core i7, but the 2014 one is obviously newer, faster SSD, newer CPU, more updates i presume and stuff like that. The 2014 is more expensive by about £60.