I agree with the current 0.5 crystal. It is like the 0.5 horses you get when building stables and NOT HAVING the Mounted technology. The iron mine I think it is the same, but can't remember.It should be the same anyway.
In fact, I even would lower it to 0.4, so if you want more, then you must do the research. That means, that without proper technology, big part of the resources are wasting on the process of getting them, or on the other side, even being ignorant on how to harvest, you still can get a little of resources.
Talking about resources costs, the problem I see is that the requeriments in crystals/iron is not well implemented. An axe 2 iron, and a sword only 1? Or the helmet, 2 iron for 2 defense, but the shield 2 iron for 3 defense? Sorry if that is not correct numbers, I can't remember now, but I realized of that... Maybe they should introduce decimals in the requeriments to make items more balanced cost-benefit,. For example, 2.1 an axe and 1.6 a sword... But that...it is more a tweeking...