I'm looking at the 2.3GHz i7 model on craigslist. Due to a minor screen crack, I was able to talk the seller down to $460. It has a high cycle count of 560 and the seller claims it has never been repaired or given him issues. The RAM is 8GB and the drive has been upgraded to a 1.5TB SSHD. I've heard about the problems with these particular models. Is this too much of a risk or should I go for it?