Some tuners will charge a reduced amount for retunes when you add parts.
The only canned tunes I see on Auto anything.com is the Superchips flashpaq tuner, $350 with estimated gains of 40hp and 50tq. All three of those numbers are high, a stock LNF with a hand tune might see those gains from a professional tuner. Canned tunes are designed to be safe so I would expect closer to 20hp and 30tq. The price is about what I would expect to pay for a dyno tune.