Answered Premium expansions

[Hekata]

I was considering getting an expansion now that they are on sale, but I see that the expansion has to be placed right away and I don't want that. With my current layout I still don't know where I want the expansion to be and I was planing on waiting to get at least 2 or 3 before deciding where they would be the post useful. So while I suspect what the answer is, I still want to check if there is a way to buy it and store it in case I'm missing something.

 

[Muf-Muf]

Expansions cannot be stored that way, no. When bought via the Build Menu, you'll have to place them in your city. The Diamonds (or Coins, for Research Expansions) will be deducted when you place the Expansion.