If you're a pure top on RM, I'd say the expectation is that you have at least 7 (advertised as 8 or 9). Not sure if you're allowing vers or vers/bottom guys in your search, but based on my research in the NYC area, those are the guys that usually have 'Boyfriend Dick'. But yeah, you're probably right that the market prevents lots of guys that WANT to be tops from being escorts if they don't have the size. Bummer.