Another data point: I bought up the supply of construction goods from the Coriolis, and noticed that restock was particularly slow, as well as small for goods like computer components and survival equipment. This might necessitate building another industrial settlement (as I only have one atm) and maybe an extraction settlement or orbital as well to see if this speeds things up somewhat.
From my experience: Fix security. In case you have negative security, you will never have a prospering market.
Check out my post at the top of page 26 in this thead what happened to the market when i went into medium security for the first time.