Also have the fine scale exponentially by data items.... data set of 100 people with 2 items (name and email = $400 total or ($2x$2=$4 per user x 100 users)).

Data set with 1 million users and 10 fields per user would be $1B and $1,024 paid to each person...

Then make companies bond their liability - with recourse against anyone up the chain of title if the data was purchased...

Perhaps a bit draconian...