Zombie I agree with the price (hopefully) of the boxset being more attractively priced than buying three separate blu-rays (it usually is in these cases), but you're making logical arguements. I am not logical when it comes to such things.
I bought Alien and Aliens 1 discs on blu-ray for $15 a piece when for only a couple bucks more I could get the whole anthology with two extra movies and all those extras. I don't even loathe part 3 and 4 I just think they're soulless sequels and I'd never watch them nor the mammoth amount of special features, so I had no need for them.
So I'd be happy if in this case they released the single movies alongside the Indiana Jones boxset but price the movies at $25-$30 so the boxset looks like a bargain in comparison and I'd gladly shell out $75-$90 for just the trilogy. I'm sure the purists out there would happily pay $30 just for Raiders.
As for selling off Skulls* I'm sure with this announcement they'll be a whole bunch of used Skulls* blu-rays going up on ebay in anticipation of this boxset, flooding the market.
*Does not refer to the Paul Walker film from the late 90's *shudders*