If you're just getting the handheld tuner, you'll still need someone to write the tune files for your car as you make changes. I use the SCT XCal2 with the Pro Racer Package software to tune/datalog my cars. That software package allows full access to all of the parameters available for your particular EEC, so that you can write the tune files yourself. Be forewarned, the learning curve is pretty steep, and you can screw things up pretty easily if you don't know what you're doing.
I can't really help you. I haven't tuned a car since they got rid of points and timing lights. My tuner makes small changes like changing gears for free. Other changes are minimal costs. I know a guy who tunes his own car using a laptop. He bought the tuning software from SCT. It's not cheap.