Ported intake gain?

I contacted 3 companies that do lots of porting. To my surprise all 3 of them said porting an intake, ET will NOT change. They said maybe (a big maybe) up to 15 hp on an engine dyno but will help nothing on the drag strip. Prices were from $450-$900 to port an intake.
Isn't that funny how they tell you it won't do much and gives you bout 15 horsepower...then charge 450-900 for it.
Either they're doing it wrong or they dont like doing it eh