Well, honestly speaking that I've never seen people selling their own data for a few measly bucks as their data is worth a lot compared to what they get paid for it.
A lot have done it in the past in exchange for token that are valueless in the name of airdrops, bounty campaigns, exchange sign up bonus
It's actually priceless. And BTW, would you mind me asking what is the noble cause for which you are asking others to help you out with KYC?
He could be planning to use the accounts KYCed using strangers' documents for criminal activities such as money laundering, transferring and trading off stolen funds etc. and once law enforcement starts tracing the owner of the account. It will be the person who solder their documents who will end up getting traced and not the actual criminal.