I printed a few images for a photographer friend of mine a couple of years ago. She has a very different style than I. The toughest part was getting the images to her for approval or changes. But if I did it more, I think I'd have a better idea what she wanted and get to it faster. It would definitely take more than beer (or wine) money to do it more frequently for multiple people.
And she just gave me some negs from a project and wants to see what I come up with (I modeled).