Come on now Bro,
I have seen guys all over the net selling the entire PI packages (heads,cams,intake) for around $300. Some wreck their Stangs and take the motor out, some swap in 3 or 4 valve motors, there are a lot of PI packages out there going for less than $400 and some little mileage on them. $1050 for 10HP is a little far fetched.
But I'm still having a hard time believing why you would port or keep NPI heads when PI heads have way more potential...
If the NPI heads are so good, then why doesn't Fox Lake or Patriot Performance sell ported NPI heads? They don't, they sell the ported PI heads. Ported NPI heads may flow well, but they are still limited. The PI vs NPI package likens to a 87-93 head,intake,cam package vs a 93 Cobra head,intake,cam package. Of course you can port the 87-93 heads and intake, but the Cobra intake & GT40 heads have way more potential..
But even a Cobra intake has its limits. Of course a ported Cobra intake flows up there with Edelbrock,TFS, and Holley, but it has to be ported, whereas the other ones are out of the box stock. Now port those bad boys, and it's Whoaaaa Nelly. Bottom line is, "If you're gonna upgrade, upgrade." You wouldn't drop in a 700HP motor and upgrade the fuel system and then leave on 19lb fuel injectors, or keep the stock cooling system, or keep stock ignition system.
Trust me, Ford tries to save every penny they can. If they thought the only thing choking perfomance was the intake, they would've only made an intake upgrade and kept the NPI heads and saved millions and millions of dollars because designing a new head isn't cheap, but they didn't. They upgraded the heads also because they knew the PI heads had more potential than the NPI heads...