Collect 8,000 gold, and receive ... 1,000 elixir?? Wth?

So if I've got this right, to get those castle walls that cost donuts, you either pay the donuts, or you grind out elixir to upgrade the castle for which you want the wall, past level 20, until you get 105,000 elixir. And then you get one wall.

So if you can pull in 18,000 elixir a day it will take about 6 days to get one wall that way.

Right?