Hello and
Hope you are able to find a plan that works for you. There is a thread here for the IP diet but yes, it is quite expensive, along with being extremely low calories. Would probably end up costing you more than seeing a doctor.
However, you can eat healthful foods and develop your own plan without an expensive diet program (note I am NOT knocking IP... a lot of people are on it and love it). If you can't afford this, why not check out something that is in your budget?
You don't need fancy, special "diet foods." There are lots of healthful fruits, veggies, beans, greens, nuts, etc. that will be good for both your health and weight loss.
I can't say about the 1200 calorie diet... my doctor has told me to never go under 1300 but then I am tall and built large.
There is lots of support and encouragement here... just check out the forum and find where you fit in, and work at developing an eating and exercise plan that is workable for you.