When anyone will investigate, it will look like a suppplier came and sold some sugar at high price, then he came back and sold a lot of sugar at twice the previous price, but that's it. He sold all of it, and why will they investigate?
Because that's obvious price manipulation, and who manipulates the price? The one who sells at even higher price because he earns the most right?
(Nah, he just a pawn that walked into a honeytrap xD)
But yeah, why would you need to be a fiancee of crown prince (like Isis wants) when you can earn a literal mountain of gold instead xD
I dont think she needs to marry a man, she just wants to look better than the ones who caused her initial ruin. So i say marrying the crown prince would pretty much shut everyones mouths and even so she would be a business partner not just some "pretty prostitute" so i am all here for her overwhelming victory in finances, authority and the her knowledge coming to light showing her current family as insignificant.
@Psychronia
You probably weren't asking for an answer but (a little bit of spoiler but nothing too specific really)
As far as I can remember, in the novel it wasn't really specified if Isis was the mastermind behind it. But all the same, it was related to Mielle. But Aria concludes that Mielle is way too stupid to plan all these things by herself, so someone was giving Mielle evil advices.
Like that awful nanny/maid she has, who will be punished by aria later on.
Of course Isis plays a huge part in the grand scheme of things.