I will completelly dodge your main question for the 1st part of my response and simply ask you to please consider very very carefully about investing or risking anything substantial in a business aimed at weightloss, even in an apparently niche market, its a hugely contested market and the chances of your business being shat out of the ugly end might possibly be very high!
Nice sentiments and big thinking are one thing, business is another, its all too easy to think big you need to make sure that you are going into this with a business head on.
BTW, I have little to no knowledge of business, I am just trying to approach this from another angle.
To answer your posed question, no I wouldnt pay you a penny, nor would I pay weight watchers or any other "support" group.
My reasons being that I can read, do simple arithmatic and do not need someone to simplify the maths for me, in addition I own a set of bathroom scales, a set of kitchen scales and a clock/calendar + a tape measure thus can keep track of things myself! I also like to think I have a reasonable knowledge of general fitness and training. If I needed help, I would pay a trained, qualified professional, with a track record and reputation of helping others, not themselves (helping others and helping yourself are two very different beasts) to back up the pieces of paper on their office walls.
As a side note, I think the amount of weight the leader or guide has lost to be completelly irrelevant, what counts is knowledge and the ability to apply said knowledge.
BTW, I dont meant to be disrespectful to you or anyone else who does enjoy success as a result of such groups and methods, just in case this is how it reads, its simply how I would go about things for myself.