The easiest way would be to reduce the tourism income and/or increase the prices of resources.
Just to make sure that it is not possible to buy all resources you need and mining becomes not useless until midgame. Special resources should be much higher increase.
The mining system should be the most important mechanic to generate resources.
I will update this post with more ideas in a few hours when I'm at my computer...
The availability of the marked could be limited to only every 10 turn like the citizens.
I thought the whole day about that system and will show you my finished idea in a few hours in a new post called:
Concept of a round and closed government / economic / food system