This has come up quite a bit in our family since David and I are both "creative types" (but in different fields) and are both trying to make at least a part-time living at it.This is how I look at the issue of "giving away" creative services or end products. Most people can't fix cars. They don't have the training or even the natural talent for understanding such things. They wouldn't expect to get their car fixed for free.
Mechanics have a skill that I don't have so I pay them to do something I can't do. Giving them money is the way I acknowledge their ability, thank them and allow/help them to continue working as a mechanic so that the next time I need my car fixed, they will still be in business and I can again have them fix my car.
I wouldn't go to my local garage and ask the mechanic to fix my car for free. (If you happen to be opposed to this capitalistic metaphor, just use bartering and imagine trying to barter 50 doilies for replacing your transmission.) But I might ask my buddy who likes to work on cars on the weekends for fun to fix my car for free. So as a creative person, I have to figure out how much time and money I'm willing to piss away for the love of it, and most importantly, for WHOM I'm willing to piss it away. It's my experience that creative people, me included, tend to piss away their gift for the wrong people, at the wrong time, for the wrong reasons…for which I admittedly have no right to blame the recipient of my free services.