wizofoz

Personally I think it would be fine, but Im sure there are others that would disagree with me. I dont believe there were too many changes from 2012 to 2013 to level I. You could probably find somewhere if there were and then decide yourself if its worth spending the money to get new schweser materials. Youll be getting the CFAI books anyways so anything that may have changed in the year you could refer to the real books for that.
To me, it totally depends on your financial situation. If its worth buying new books or not spending the money and putting some extra effort in.