The idea is very interesting. I like the idea of minimum $35/hr. To take the idea further, avoid using pricing as a signal, and protect the buyer as well, $35/hr could also be the maximum. That will take rates out of the equation. After that competition will be to get the most rewarding work, with emphasis on work quality.

As a developer, I may even be willing to pay a screening fee, if I would be able to get good quality work.

Apply to YC. You will get support, ideas, and make great relationships. That will also help you get traction and gain credibility.