Hello! I'm planning to buy a used Macbook Air. The MJVE2LL/A model (early 2015) is being sold at $850 whereas the MD760ll/A model (mid-2013) is being sold at $700. What's the difference between the two? Is it worth the extra $150 and get the newer version? I'm mainly using it for school (ie. Microsoft) and web browsing/ youtube videos. Thanks! I'm a total noob with computers.