It is not a silver bullet to solve the Deck Capacity Abuse as you have written, but the costs would certainly be lower and be fairer for the smaller players that does not have hundreds of card farms, and there will not be a lot of need to have a lot of puppets to store cards (or sell/buy to exceed that capacity).
Plus, the big farmers often have a lot of bank anyway, so the reduction of costs would be welcome for them, too.