I think I've encountered a bug as I have over 800 credits and it's not allowing the option to buy the new chems. It just says "Can't Afford". The try system works fine though.
Is it supposed to cost 200? or does it have a higher price?
Edit: Went back to the ship and all three were unlocked through still shows the question marks next to one and still says "Can't Afford" at the shop.
So you can buy them just no indication you have at the shop.