depends on where you are and what's offered in your area. there's a guy here in my area that has an above ground dyno roller system that charges $90 for 3 pulls.

there's another tuner in my area that charges $60 for 3 pulls on an in-ground system.

if there's no one to compete with in your area, more power to you. if there's competition, especially with a reputable tuner, you'll have a hard time unless you can undercut his pricing a good amount... or build up your reputation for putting out some powerful cars or at least assist in building some nice rides.

paying for a dyno is tough... no one in the import world does much dyno tuning cuz they're too cheap. they will TELL YOU they have tuned their ride, but usually it's a lie. only the most serious will properly tune their car.