Somebody on the dark web is asking for $2 million in BTC for this exploit, which they claim will allow somebody to take control over someone’s iPhone. If an exploit is worth that much money you would think the seller might be better off keeping it a secret and getting rich by exploiting the vulnerability for their own benefit.
Yes, it's very possible for someone to have data that is worth a large amount of money and still want to sell it out to another person on the dark web.
I have read stories of hackers who extract information, sell it to those who will make use of it, get their money, and take off. Those who buy the data will be the ones who make use of it in their own ways to exploit the data owners.
I don't believe the person who placed the bid has access to such data; if not, they could have been pricing on that speculation on the internet already, but if such data does indeed exist, then I don't doubt the selling, as they can actually sell it to someone who can make better use of the information than them.