They're already willing to give out the first expansion free to those that obtain the game early enough. I was a collector's edition pre-order, but I have confidence that the game will eventually be worth what was paid. Lowering the price could hurt an already hurt Stardock. They've pretty well written the game off as a financial loss but are still committed to fixing what is wrong with it.
So technically, whatever price the expansion goes for is going to be something that we wouldn't have to pay, so we are getting a discount in a way, in spite of Stardock's already hurt finances. I believe Frogboy made a post recently stating that they'd actually increased the Elemental team in order to speed up things and fix their mistakes, creating a game that the gamers want.
This is just my thought on any sort of a discount. People who purchase the game after all the hardships and issues are fixed shouldn't profit from what those that supported the game from the start were given, because it's our support, not future support, that is getting the game fixed in the first place.
That's like discounting the next generation of a car because the first generation buyers found a flaw and it was fixed. Only the original owners should benefit, because future buyers are getting their money's worth.