For lBlack Cocks: charge them triple the usual cost and service them using only a silicone fleshlight that has already been used by other men but is perfect for fooling them into thinking they are really in my mouth or vagina.
For White Cocks: Just charge them half the cost and offer them the most passionate blowjob in the world and anal or vaginal penetration, whatever they want, but if they agree to get into my cubicle to fuck me in person, then the service is free.