People are willing to pay large amounts of money for anything related to human breast milk out of either belief that it's somehow magically better than other forms of milk/cream/fat as some sort of ultimate expression of "organic" or "artisanal" products, because of a fetish for the stuff (as seen here), or simply to do something "scandalous" like eating some woman's breast milk ice cream as a "delicacy".
When people are throwing large amounts of money around for something, then where there's demand, someone will supply.