I could see a declining fee model. Just a thought.
We are trying a low FODMAP for my wife. I could see her paying for it for 2-3 months, then we would probably find that expensive at $29/w...but, if after 3 months, it went down to say $29 per month, then it would totally make sense as we would use it a lot less, I think.
At least if we compare to when she stopped gluten, lactose and a few other things 6 years ago...the worst was the first 2-3 months.
Could the high pricing be because this is really a guide to a solution -- once customers have need for a guide, they'll stop using the service; that is, churn is naturally built in due to the nature of the service.
I could see her trialling a comprehensive ($30 a week) package for a few weeks, then dropping to a less intensive (~$10 a week) package that kept her on the right track.
I personally don't think she would pay $30 a week unless the service gave her a significant material difference in lifestyle (which I certainly imagine it could have the potential to do).
i.e., it would help you with churn a bit, I think.