Greenland is strategically and economically valuable, and likely to become more valuable. It would be a good investment for the right price. However since it is probably less than a decade away from independence, it would be a dick move for Denmark to sell it now, and they weren't inclined to sell it in WWII, they just let us put some military stuff on it, which we still have there.
I'm not anti-Christian. I'm anti-stupid.