Can Crafting be Profitable?

This is limited to potions and traps. Any kind of ammunition cannot be sold.

As for the value of components vs items, as an example:

A health potion can be sold for 6 shards. However, to make a health potion you need 2 "Rich meat" and 3 "Fatty meat". Rich meat sells for 3 shards per item, and Fatty meat sells for 2 shards per item, meaning that by selling the items, you get double the value of the potion.

The upside is that a lot of the time, Potions and traps are found in loot boxes or treasure boxes, on human enemies, etc. So in those situations, you can fill up your stock of potions and traps fairly quickly, without expending your meat stocks.

As for stocking up on ammo parts - firstly, you can never have too much Ridgewood. If you need to keep things limited, I keep it down to 3 stacks at the very least. For all other items required for ammunition, I keep at least one stack, two stacks if I'm feeling generous (items like blaze, chillwater, sparkers, etc).