Tangentially, it's interesting that the US declassifies things and they become publicly available.
What you need to do is pick an entity that has the information you desire, and recursively enumerate the graph of all business deals which involve the sale of that information (their downstreams, effectively). After that, you do OSINT to map out all of the employees of every organization that has access to these databases. After you have mapped out these tens of thousands of individuals and their likely social graphs, all you have to do is pay one of them a relatively small sum to do a query on your behalf.