Our goal was to be able to take a stock truck and not have to make any other modifications to it in order to run in high out put mode. That is pretty much the cap before you have to start worrying about EGT's. -
That will depend on the vendor that you deal with. To list some they would be Jegs, Summit, 4 Wheel Parts, Napa, Autozone, O'Riely's. IIRC you are looking somewhere around $450 or so. But I haven't checked on that lately. I do know that some vendors will run a special on them from time to time. -