[PipeGuy]

Basically at the end of a job for a new customer they have told me that they want some more work done...he said for me to call him in a few months or whenever I wanted or basically when I wasn't busy and sit down with him

I hear "I might want to do something if I can do it at a bargain basement price ".

I say try and get them to pay you to do a "budget" estimate now (this'll really seperate the wheat from the chaffe) with the stipulation that the estimate fee will be credited towards the work should they move forward within a certain number of days or weeks. You could even offer a guarantee that the "build" estimate won't vary more than x% if the work is started by a certain date.