[uberduber]

If you are not already going to a large academic center in a large city, I would start there. Also depending on your condition and specialty it is fairly regional. For example, most of the good geneticists are on the east coast.

In large cities with rich people there are cash only and concierge doctors who will spend the time needed with you because you pay them for it. The going rate now here in Los Angeles seems to be $1000/hr for an appointment, though they do spend time outside of that on your case of that which they don't charge for.

If money is truly no object, there are services that you pay money who will do research, have connections to top doctors, and ensure the correct diagnosis. The best known one is Private Health Management. There are some smaller firms often started by people who used to work there that are more affordable. Years ago when I talked to some of these my personal case was around $50-100k which I don't have.