Chris
That sounds very reasonable and logical. But that doesn't seem to be the same as what you're looking for here.
If I were to sell your friend a machine and program the particular part that he's looking for, I would get paid accordingly for that. But, it's the support afterwards that would be the issue. What happens when your friend calls me on a Tuesday at 10:30 because his machine isn't doing something right? Do I stop running my business to help him? Do I do that for free?
In your scenario, your support is local to you and you have an agreement that you'll pay him for his services.
I would recommend that your friend do as you did. Buy a quality machine capable of doing the job, and hire some local help as needed to program it and tool it up.
There are just too many things that can cause problems that would be tough to fix over the phone with someone who is completely un-skilled in machining and cnc.
I really hope it all works out for him. I like it when people try to bring ideas to market in the pool world.
Royce