With a bigger population, I think there would be a bigger market for T2/T3.
And thats really the central issue.
With more players there would be more drops, more demand, more supply, more arbitrage trading, more competition, some items will go up in value some will drop, more producers would use the market instead of avoiding it... not just for modules but for all items. Its called Economy.
There are things you can do to encourage trading, like giving traders more tools to market themselves, but it will never really have the same impact as simply having more customers and more competition.
even at its peak of some 900 players the market was tepid at best.