It's a decent chunk of money to spend if you have no power adders. The tune alone only adds a small touch of torque and horsepower, probably enough to compensate for wear losses over the years. If you ask for parameters to be unlocked, you can adjust transmission shift point and firmness settings. This really changes the feel of the car and what makes it worth it. You can also change the top speed limiter (make sure your tires are speed rated), idle in gear/out of gear speed, richen/lean the fuel mixture slightly, and adjust spark timing throughout the RPM range.
I have never dealt with him, but hear he has great customer service. Make sure he's willing to go back and adjust the tune up to a year later so that you can experience it in all weather situations. You don't want a bunch of preignition from overadvanced timing that only rears its head in the summer. Tell him your concerned about pinging and ask him what parameters to log so he can look at it and adjust. This should be done in the first few days, but he should still be willing to go back later on (make note of the pids to log so you can do it on hot/humid day).
I have a street tune and a track tune. Track tune actually backs off timing since I'm spraying nitrous, plus I can tweak air/fuel as needed so I get a little more for my purchase. I also bought a used Xcal2 for cheap which should work. This will save you some $ or let you afford another tune file.