Working for myself, and often spending my time and giving information to people that will never end up resulting in income to me, I can see both sides to the story. It's fair to set a price for certain services, that will either be competitive or not.
BUT, when I have a good, repeat or faithful customer, there would always be a better deal offered. I'm not saying anyone here is this way, but there are people out there that feel that it is their right to be inconsiderate and rude in their quest to save a buck. I'm honestly as frugal as the next guy, but I also get satisfaction in paying fair prices for good service, and especially when I think it's helping out someone I like.
It's like the several times Lindsay machine will let me bring in my bike to help with stripped bolts/threads the day before leaving for a race. They charge a fair fee, but never over what is expected, and still go above and beyond. I always want to tell others about their great service.
Procycle is the same, and I also try to give what business I can now, because they have gone out of their way for me.