Since I've been excluded from the beta test I can only guess the game play based on the limited demo.
It seems to me the game has a major economic problem.
Currently, building parts and ship cost are one and the same. This means ship builders don't really earn any money if they don't do mining and refining ores themselves. Only mining and refining ores bring in the money. There's no difference in earning for those who only do mining and those who build and sell ships.
In the real world if you build things yourself you only pay for the resources. But if you sell your products you also charge for your labor.
Therefore, I would like to suggest a minor addition to part cost calculation. Parts will require resources to be build as is but the final cost factors in extra labor cost. Naturally, this parameter should be accessible for modding.
With this there's not only a clear difference between those who do only mining and those who sell ships but also a better cost based balancing between ships.