mods
The developers can't keep adding more and more to the game. Eventually, we have to start throwing more money at them. That's the way I see it. Nothing is free, everybody has bills to pay.
It might be stupid for me to ask, but is this game going to be easy to mod? Are there going to be instructions on how to add buildings and recipes to the game?
That way, a lot of these suggestions could be added by modders. Personally, I think it's the only reasonable answer for all of this. Either that, or DLC.
Love the game. I think they've done a great job and I want to support developers who make good games.