IMO the 'sticker shock' would knock the wind out of most people and a huge key to the success of Apple's ProApps would be gone.
How many people would choose FCP over Premiere or Avid if FCP cost $2-2.5k (heck, even when FCP alone cost $999 it was seen as a steal)? What if Color still cost $25k or Shake, which I know is dead, never got reduced from $15k? DVD SP and SoundTrack used to sell for $500 dollars each, IIRC, and, at least for DVD SP, that's still a deep discount from what the app used to sell for before Apple purchased it.