What's it worth?

I've got a friend who's thinking about selling one of his mills. My research here leads me to believe it's a 1hp Bridgeport J head with a date of 1953. It works great and comes with a lot of tooling (vice ,rotary table,collets etc..). He even has a home made 3phase converter for it. He's an older guy and I don't want him to get taken by some of the people looking to buy it.
Thanks