I am of the oppinion that all materials, comdeties and items for ship and foot, that are used in anyway as consumable.
Be that for unlocks, modifications, synthed rearms or anything else the player does.
Should all be sellable and purchaseable by the players to the players.
And not just via Fleetcarriers. As new players could profit enourmously from selling High grade materis used to synth AX stuff.
I know I would be paying in the 100s of millions for complition of an order/mission for mats.
Material traders could offer missions to complete orders for mats, those orders could be created by players. They could also alow creation of the missions.
FCs could then have a new service that facilitates the placement and completion of those orders/missions by players.
Obviously the rearm synthed ammo for a rebuy exploit would need removing.
Yeah, and I can't see a player-trading market as an economy breaker (the "b-b-b-b-but credit transfers!" ship sailed
long ago and arguably wasn't really
that much of a problem in the first place)
Worst case scenario for being able to buy/sell engineering materials or other items would be a situation like the mall in kingdom of loathing where, with the exception of no-longer-obtainable items ending up skyrocketing in price or outright not available for sale since collectors want to keep hold of what exists, everything eventually levels off at the price point where people go "sod paying that, it'd be less effort to just get one myself than it would to get the cash to pay for it".
The only real killer would be if, like the current implementation of bartenders, the price was capped at something so ridiculously low that nobody in their right mind would bother assembling a stockpile to sell.