The day you were dreading finally arrived: your MacBook is dead. Whether it’s a fatal case of BSOD or your decrepit iOS is so old it’s no longer supported by most browsers or apps — it can happen to the best of us. How you rally from this sad moment in your electronic life is what separates the strong from the weak. You’re probably hoping to replace your old Mac with a new MacBook Pro Retina 15”, but your wallet may not be ready for the purchase. A brand new Mac isn’t cheap, but a used one might be. If…