Get your own work, you can spend a lot of money with canvassers who just get you your leads, that turn to nothing.
If you want well priced work you need to be clued up on risk assessment method statements and Health& Safety as most if not all will ask for you to do that. In my opinion canvassers are a wast of money, others will disagree. I have had dealing with a few who are/were absolute rubbish. Save your hard earned mate.