Thread:BehindTheEight/@comment-26545994-20150720195910/@comment-26545994-20150722140158

the first expansion was indeed 50 gold to get an extra of 10%.

The second expansion cost me 100 gold for 20%.

The third expansion cost me 150 gold for 30%.

after that expansion it said were you normally read how much gold it cost, that it was sold out.

Now, as you can see in the picture i send you, it says 200 gold for 40% expansion.

When you bought these expansions you get it everytime you grade up the metal or oil storage in you're base.

So normally you get 3 million for 1 grade.

But i get 30% more with that grade.

So per storage grade i get 3,9 million per grade. 

I hope i awsered you're question.