I'm sorry, but you have a misunderstanding of basic economics. If you gather materials out in the world, they are not 'free.' There is an opportunity cost. If you *could have* sold them on the GTN for a certain amount, that is their value. Thus, it does not matter how he acquires those mats. The cost associated with making an item is based inherently on the opportunity cost of the requisite materials.
The OP's concern is a legitimate one. The effective cost (and I'm sure it varies wildly from server to server) of consumables is very, very high.
Game economics are not real world economics, so don't even go there.
If credits are the goal, you have options. You can gather mats for free (because time doesn't give you credits for nothing) and sell them, or turn them into items and sell them.
If you want an item. You have options. You can gather the mats for free (again, because you aren't paying anything because time in game does NOT have an intrinsic value) and sell them for credits and buy the item, or you can gather the mats for free and craft the item yourself, or you can buy the mats and craft the item yourself.
If you gather your own mats and make an item, that item has cost you time, but not credits (unless you gather through missions). No credits have left your account. It doesn't matter what the potential value of those materials is since that value is unrealized until someone purchases them for credits and thereby set their value.
Real world economics and game economics, while similar, do not equate the same when it comes to values. Again, if you are buying mats to make an item, you are doing it wrong.