It's pure "luck", random chance. Some people get all the luck -- all the drops without even farming.

I'm not far from hitting L41 a third time and I have not yet seen a single vanity drop for myself, not a common JCN helm, not even a cheap pet, and only TWICE have I seen it drop for other people.

I think you should chill and stop wasting your time. If you don't got the luck you don't got the luck so you'll have to build up to buying the vanities yourself and hope the lucky ones place some mercy on the price.