There's a thing called prepping...
Why do people think those 'raiders' who's also an omnicrafter grinded for their DoH/L gears, white scripts, and purple scripts weeks before the actual tier drops..? Why do people think they hitch a ride into those hunt trains whenever they could? Apologies, but I fail to see how it is "gatekept by the gil market."

Even much less when I re-think it again, you're only mentioning pentamelding which only requires one of the DoH to be sufficiently leveled to pentameld. Even if people level their DoH/L solely by daily GC turn ins, they'll still have plenty of time to prep.