people are still using older Macs than that,i have a mid 2011 MacBook Pro that i hope to be using for years to come,i update to Apples latest OS when it's released and that keeps it up to date,i'm not sure if Applecare is transferred to the new owner,the first owner will have purchased this when she bought it,you can always ask Apple about that,the Air is a very good machine,just bear in mind that you can't add extra RAM so try to decide how much is adequate for your needs,if you are worried about condition and you are able to meet up with the owner you could always get it checked out before you buy it,maybe an Apple store would do this for you,again it's worth asking them.