I agree that being paid a reasonable amount for time and supplies is not wrong.
My own story of charging and not charging for services.
For a while I used to do Tarot readings for friends for free. Actually I don't think I charged anybody at all as I was learning how to use the Tarot at the time. Then I had one friend(?) who started wanting a reading every couple of days. Then it was every day. Then it got to the point where she wouldn't make a decision without "consulting you and the cards".
At that point I started charging her, and to make it fair I told everyone that I was going to charge $35.00 an hour, and $10 for every quarter hour after the first hour.
Suddenly we weren't friends anymore, and she was very angry with me. But I stopped getting phone calls from her wanting me to make every decision for her thru my cards.
Many of my other friends just laughed and said okay.
But nobody asked me again. So I don't know if that's good or bad.