I Earth King Amaimon I
You'd need to make 5 million gold 100 times if you were aiming for the backwings. 5 million probably wouldn't even get you a single ingredient for the first level's formula, let alone the final stage of the wings at level 10.
And yeah, you'd lose a hell of a lot of money, because the wings are pretty much unsellable. No one can afford to buy them, and no one wants to sell them for less than they paid to make them. Okay, NOW you're just slandering at random. 5 million gold is not enough to purchase the quest itself, but once you have the formula 5 million should get you all the way to the medium Wings.
...though that's assuming you're using that gold only for the backwings quest itself and you've already achieved Level 10 in Alchemy through other means. If the Wings are all you want from Alchemy, and you don't mind missing out on 100 Achievement points, just commission a level-10 alchemist to do the crafting for you.