maybe they're keeping an eye on them. I mean the timing was too perfect.
what if it was the administrators, cause they'd have to have a lot of money....
In the light novel, it explains that it's the "Resellers Guilds" who make huge profits off of buying cheap things and selling them expensive. Earlier, they completely dominated the market of Beginner Potions, increasing the cost by about 5x, making a 400% profit but screwing over beginner players. They'd completely buy out the NPCs and anybody who sold cheaply, for either potions or for herbs. With the advent of Yun's Blue Potions, however, it started to break apart their monopoly and drive down their profits until enough players were good enough at making potions to completely make it unprofitable.
When the reselling guilds heard about the future-Crafting Guild's goals ("Provide everything at a fair price") they did everything they could to delay and bankrupt the crafting guild so that they could continue to operate and profit: namely, driving the guild permits' price up from (I believe) 1 million gold to 5 million gold and rising.
Of course, immediately after the Crafting Guild was finally made they had no reason to hold on to the permits anymore (sunk cost fallacy and all), so they immediately flooded the market with the permits to make up for lost costs. (Actually, this fact then drives the next major plot point. I wonder if the manga will bring this up sooner or later? Anyway...I won't post any spoilers so I'll just leave it at that.)
That player that was buying up all the guild permits is gonna start something... His goal is either to have a monopoly on the guild permit prices or to control the guilds themselves...