One way you might be able to work it is to have the 6 PP "cost" count towards the power's maximum PP and as you get higher levels the "cost" might decrease or something.
For instance, a 7th level character would be able to automatically quicken a 1st level power, but he could only spend 1 PP on it normally because the 6 for quicken goes towards the max, even though he doesn't actually expend the psionic focus or PP for it. Am I making sense?
E, it's just like Halinn's point now that I look at it, just worded a little differently.