Hi I am wanting to buy a used Macbook pro for use at home. Mostly just to store pics, home movies, surf the net, Netflix and my kids would likely do some school work: power points, reports, etc. Nothing heavy duty. Beyond knowing that I want a 15", at least 500 gb ssd, 1TB would be even better (happy to upgrade the memory if possible/needed) a battery that is either not very worn or replaceable and cost that tops out at about $1500 Canadian, I am not sure what I really need. Are batteries and storage replaceable on all years? I'm reading conflicting things on this. Retina sounds nice - would I really want this if I'm watching movies? If I'm not doing that much with it how much RAM would be enough? Better wifi on the late 2013 and newer sounds nice - would I notice a difference? Same with the more efficient battery use of the late 2013s. Noticeable? The increased speed of Thunderbolt 2 also sounds tempting. I would be backing up to a couple of external hard drives now and then - but would I notice the faster speed? If I get all of the options that sound nice I'll likely be way over what I want to spend on a used one. Hopefully with your help though I can get what works for me. Thanks for the time.