What is the cost to craft one unit of treated wood? 50 wood and 10 fuel. What is the price of treated fuel in the shop? 10 fuel each.
Sure there is a price break the more you craft at once, but it's not significant in my opinion. Surely it should cost much less to craft something with the materials than to simply buy the object.
This applies also to Hardened Metal, and Heavy Fabric. Why even bother crafting them?