I think you would have to weigh in on how much you'd spend on food additions, too. The cost of the Zonefast diet is not just what you spend on 1-2-3 products. And, if you are doing this for breakfast and lunch, you are going to need more than $15 worth of products per week.
I haven't had time to do my own cost comparison, enjoying the fall weather here this weekend. But, if I have time later, maybe I will try to do some comparisons. I am thinking of setting it up as a 1-2-3 meal vs. an equivalent zone-block meal using classic zone foods. I know that some may argue that they aren't necessarily equivalent, but guess I will have to do my best!