I'm an artist (meant as a craft) and I do it as a job. I'm definitely not doing this work only for my own pleasure.
So please, don't send me any requests for cooperation or for using my works for your projects, if you are not disposed to pay. I'm not providing my works for free, not even when the credit is mentioned. Please realize that this is not fair; everyone has a right to get a payment for his work. You are paying for things, which you need for your life, food, fuel, housing etc.
Art is something about this all, so why should it be for free? Not any single reason exists. I'm open to any cooperation, which is standing on a fair deal and honesty, and of course which offers an adequate payment for the used work.
Thanks for understanding.