Well thats seems more than a bit unlucky.
I got biochem and ive not spent anything on it apart from a few missions at the end to get the purple mats for the purple stims healthpack and adrenal, you only need one and can re use it over and over, its not like you need to keep making them.
I do pretty much everything in the game with my m8s and we have not been below a million since we hit 50, this game just throws money at you, everything you do pays you loads.