Plenty of PvP dedicated captains, which have their own favourite models, say like a Privateer, a Rattlesnake or a Surprise, will be more than happy to let go of marks to helpful crafters. It is quite symbiotic. You provide ships, fighters will provide results and the "rewards" with you.
Free market being free market, careful with the prices race. Greed always loses. Better to keep a fair margin and establish good comebacks than suffocating the stores with gold that becomes... meaningful.
Now, setting up a Conquest fleet, that's a Nation wide thing. And numbers will not matter if small numbers do achieve more victories ( and marks ) lending them way into the 1st rates to lead a fleet of lesser rates.