If you want more profit, get more retainers, simple as that. I know from gm's that they won't even interfere when you form a cartel to increase prices of the goods. So there is 0 chance, they will ever regulate the market. They will only do it for stuff like house selling where a lot of gil (like 100 Mio gil) might be involved, what would totally destroy economy. But the retainer MB system regulates itself so no chance for you, sorry.