i currently co own a performance shop. We have been going since Nov of 04 and are doing great.

we are contamplating on getting a chassis dyno....i am located exactly in the middle of Milwuakee WI and Madison WI

Is it worth it?
will it pay for itself or make us money??

yes! if you can get the money and the proper training. I own a shop here in mid-missouri and I know the owner of another shop that does mostly tinting. But they've got a dyno and charge around $100 for a run and tune. That's only 1000 people to pay off the typical $100,000 price tag they come with.