I think this could be a cool thing in solo servers, possibly warring servers too but might be two different things.

Pricing would need a Sell on private market, but no option to buy on private markets.

Sell Price on private market increases as game turns are given, these things need to get more expensive as the set progresses with $x increase per game turn. If private market sell price overtakes the price players put missles on then its an auto sell.

market starts at turn 400 game time. Completely unavailable before this... not as players play turns

start at $2,000,000 sell on private market. open pricing on public. at turn 400 game time. 1000 acre max tech making one per 20 turns. $100/acre/turn x 20

needs to be an increasing formual for price. private market sell price. something like this.

turn 400 $2mil
by turn 800 $ 8 mil.
turn 1200 $ 32mil
turn 1600+ $50 mil

Greater demand for warfare tech and sdi tech :)