Yeah, the tune is actually even cheaper than that. You're just paying a bit more for the PCM. But you can get all of the gains you would from most other custom tuners.
More HP/TQ, shift points, shift firmness, rev limiter, speed limiter increased, possible increase in gas mileage, and many other adjustments to improve drivability and performance. Such as reducing that annoying lag you feel when going WOT off the line, etc.
It's hard for any custom tuner to give you an exact number for HP/TQ increase since every vehicle and tune is going to be quite different. Some might give you a rough "guess," but honestly, it's mostly irrelevant.
But if you're interested, give him a call, tell him what you have, what you want, and give it a try! Good luck!