The MC isn't the best at crafting and pays the price of opportunity cost.
I'm not a painter. I can take a bunch of expensive paints and craft a terrible painting, and it will be worth less than the raw materials. I'm also not a tailor. If I tried to make a garment out of an expensive fabric, I would just ruin the cloth. I am also not a jeweler. Given a bunch of gold and gems, I'm not going to be able to make anything that's worth more than the raw materials alone.
Crafting only adds value commensurate with the skill of the craftsperson. 159
If you don't have the tools and skills to turn raw material into finished goods, you're at best wasting your time trying by making something that isn't any more valuable than what you started with, and at worst, wasting the raw materials because you don't know how to use them properly.
Even if you have the tools and skills needed to craft, in many cases it's still more profitable to let a specialist do it for you due to opportunity cost and a thing called comparative advantage. Basically, you can craft an item yourself, but the time it takes to do so could be spent doing something else that would have been even more profitable. Here's an example:
Suppose you have collected 10 Foos for a Bar potion, and you can either sell those 10 Foos to the potion maker for $10, or brew them into a potion yourself and sell it for \$20. But in the time it took you to brew the potion, you could have collected 20 more Foos, which could sell for an additional \$20, rather than earning only an extra \$10 by brewing the potion. If this is the case, you'll be more profitable by selling raw ingredients than by brewing potions, despite the fact that the crafted item sells for more!
What's really interesting is that this arrangement is also more profitable for the potion maker - if he's more skilled at brewing potions than finding ingredients (e.g. if he can only collect 5 Foos in the time it takes him to brew a potion), you will both be more profitable if you only find raw ingredients and he only brews the finished product. Both of you should only do the one thing you're best at, which for most adventurers, is not crafting a wide array of useful items. 893