My sister is doing it and the price tag doesn't stop at the course - you will also spend a lot more on food. My advice is to sod weird diet plans and spend the money on fresh, in season foods including lots of veg, some fruit, lean proteins and good fats such as high quality olive oil, nuts and oily fish, cutting down on wheat and sugar (for some people dairy is also an issue, try it out), drink a lot of water/fruit tea/green tea, avoid processed food, add some moderate exercise and start sleeping more and more regularly.
If that doesn't work, Metabolic Balance won't work either.