Well, that's usually up to the market.

Like if both Noir and I buy a ball of yarn for five bits we'd need to sell it for six bits or more to make a profit.

better be some damn good yarn

Anyway! So if I try to sell it for ten bits and he sells it for six, obviously you're gonna buy it from him right? So I'll have to lower my price to be competitive.

Did they teach you this in super villain school?

This is all pretty basic logic...