Like Glen (spinbiscuit) below, Dr. Engel did my surgery at GWU Hospital. My surgery was in September. Dr. Engel and his staff are wonderfully friendly and he has a reputation as the most experienced with DaVinci in this region (700 or more surgeries). He does 3-6 surgeries per week, I believe. Dr. Engel was one of two surgeons recommended by my urologist. The other surgeon was Dr. David Lee at Philadelphia Presbyterian Hospital or something like that.
I'm sure others can recommend surgeons if you want to go out of this region.
My urologist did not recommend Johns Hopkins since they do not do DaVinci prostatectomies. They believe that 6 years of experience in these has not yet proven them. In fairness, there are others on this site who have had good experience with open surgery at Hopkins.
As far as cost, the billed amounts (before my insurance got the hopital/doctor/etc to agree to accept less) would have totalled just under $30,000. I believe the hospital bill was $18,000 and surgeon's bill was $7,500 plus other bills like labs, anesthesiologist, etc.
I certainly wish you luck in your search.