Codewar, we all are willing to help you, we just need more info before any of us can.
What's in it for this "guy"? What is the advantage to hiring you as opposed to bringing you in as a sub?
What is this guys reputation? Does he pay his guys on time, and no matter what?
How many other people have taken this "offer"? Anybody you know? How long have these other guys been with him?
The first thing I would do is google his name and see what comes up, then I would investigate a lot further. Maybe show up at one of his jobs and strike up a conversation with a couple of the other employees when he's not around. Do they get their checks on time? Have they gotten what they were promised in a timely manner? Etc, etc, etc.
If there is that much money in it, there's no shame in taking the time to investigate and find out what is really going on.