How to change store prices?

[Yuurg]

Hello, I am making a mod and I would like to know how to change the price of the oxygen system in stores. If I make a ship without O2 and find one in a store, it's 0 scrap. I want it to be something like 20 scrap, so can anyone help me?

[kartoFlane]

In blueprints.xml, find the oxygen system's blueprint (<systemBlueprint name="oxygen">)
At the bottom of the blueprint tag you'll find a <cost>0</cost> tag - the 0 inside is the cost of the system at a store