I think 38-50k is a very fair salary for a foreman. He is doing everything that you would have to spend time doing, but frees you up to grow even further.
It really is a no brainer IMO. These people are the linchpins of your business.
I know a foreman for a Atlanta based business that makes 50+k as well as they other perks like truck and benefits. I think he is responsible for 12 guys.
It is similar to having another business as it can run itself.