Thank you for turning me on to bricklink! I wasn't familiar with that site and I was disappointing by what Lego was offering.
What I'm really hoping is that Lego starts fulfilling demand for old sets (please start making classic space sets again), but I doubt it.
In some cases, they don't have the molds to make some of the parts anymore, but even if they had to substitute some parts, people would buy them.
It's been four or five years since I've bought anything new from Lego; the few original themes aren't that appealing, and the licensed stuff is pretty tired as well (how many times do you really want to buy slightly different Millenial Falcons or Hogwarts Castles?).
The host of chinese high-quality knockoffs show this is possible, economical, and probably not even difficult.
I've heard the monorail space sets are so expensive because of the "lost mold" problem. I'd understand if the parts only existed in old video footage, but there literally are thousands to tens of thousands of examples of this, available on the open market for a pittance to a large multinational multimedia company.
I've heard there are people that invest in Lego, but who cares about these people? And if you really care about them, just release sets with small variations from the original.
I think they should go the upscale route, just release massive all-in-one sets of all the sets from a year, like 1979 classic space or the explorien.