I was playing a game as Sophons aiming for a Science victory and received a pop up stating Attacker ships where in high demand. I made a design that had just the basic level 1 components (no strategic resources) and had a city with very high production pumping 4 or 5 of them a turn to sell them for over 1K dust total. I did this for the rest of the game (past the high demand event - though I think this never affected sale price), adding in more idle systems, and dust became a non issue even without me really focusing on dust. In turn, the excessive dust made production easy, as I could rush buildings, ships, whatever I needed. This also makes the tech that lets you convert 25% of production to gold obsolete, since even 1 ship would sell for more than 25% of my highest production. I ended up winning by bribing most other empires into an alliance.


Even though sold ships do not appear on the Marketplace, I believe they should have their price lowered as you sell more similar to how other resources behave. This can be tracked by Hull type to apply a multiplier after adding in extra value based on the amount of strategic resources and upgrades used for the variant. It would then slowly increase the multiplier back to 1 if no ships are sold over the course of some turns (so you have that option if you need a dust infusion). The price would have to be tracked per ship sold instead of per transaction; otherwise, one can stockpile 20 ships and sell at once to completely skip this idea. I also think either base prices need to be lowered or the recovery rate would have to be very slow. I was able to sell 1 of those extremely basic ships for around 300 dust, which was about half my dust income across my empire at the time. Note that I was able to make around 10 a turn with my idle systems.


As long as they remain being unable to be repurchased from the marketplace, I don't think this should be tracked across Empires (e.x. Player A sells 10 Attacker ships tanking the sell price for Player B) as I see ship selling as a quick way to get some extra cash to purchase something else instead of another income source (since I think it blows regular empire income out of the water).