As the world is getting colder and more harsh, crops are getting harder to grow, perhaps it is time that the food so easily picked up right off the ground become slightly more valuable? I don't know exactly how much more time should be added to the CNR before it respawns, that is up to others, but it makes sense.
Fruits
Nuts
Grains (This was the main one I was thinking of when I came to this idea, to make breads and such more scarce)
Plants (cotton in particular, aloe, sugarcane, ginseng, etc.)
And Trees too would have their growth stunted by the drastic change in weather over such a short time. (and would be harder to find trees of a quality worth harvesting)
I do not suggest this to exactly hurt crafters (particularly beginning crafters), but it is how the world would naturally tend to become given past events, the little things would become much more precious and sought after.
The idea might be simply changing a few simple bits of code, or it might be impossible without effecting every bit of CNR, I do not know, it is only a suggestion.
