Master Ball prices dropped precipitously after they were available in the Ppwn Shoppe – everyone who wanted to sell them loaded up when they were for sale, now they’ll be a bit above that purchase price until they get rare again.

The scarcity of Floyds is only tied to the number of people grinding for them, and as they become cheaper it’ll become less worthwhile to grind for them, prompting people to hoard the Floyds they’ve extracted or grind for deliveries instead, so they’ll eventually become rarer/more expensive again.

Only other thing that would lower the price is a drop in demand, which won’t happen until everyone (or almost everyone) who wants one and can pay for one, has already done so.