There are many so-called affiliate launch professionals out there, but unfortunately most are self-proclaimed and have no real success in launches, recruiting affiliates, etc. Not only do your research, but if you find someone that you really feel would be a great launch/JV partner, ask for details about their experience and testimonials.
Mark is right! You will have to pay a fair price, but if you find someone that has a rock-solid track record, then it will be worth every penny.