Just now created a base for farming dark elixir. Not 100% sure what I want to use it on yet.
Minions (level 3) - 20,000
Barbarian King (level 6) - 22,500
Hog riders (level 4) - 40,000 (and 12 days :o)
I want better hogs badly, but people are bending over backwards to steal my dark at below 20k, so that will be really hard.