Technically, God is an amateur. No one ever paid Him for His creative works, after all.
I would say that lots of people have paid Him for his works; animal sacrifices, tithing, etc.
I've got to vote for amateur on this one too. Considering he could create any of those things with a thought, they're not really payments at all.
This raises an interesting point. Is payment what I give, or what you receive, or both? If I give you something that I consider valuable, but it's worthless to you, have I paid you or not? What if I give up something that is of little or no value to me, but it is of great value to you? Does it require both sides to form 'payment'? Hmm...
I would say it requires both, but it does not require both parties to view the payment as any great value. If I buy something at the dollar store I am paying the agreed upon price, but I don't think either side would consider it that great of a payment.
Alternately, if I get a new TV, and offer you my old TV (this presumes that you want it) if you help me move the new one in and the old one out, I will feel like I got the better end of the deal because you helped me with the heavy lifting and took that old TV off my hands. You would feel that you got something of value as well, as you now have a TV where you did not before. Even though I did not value the payment, you did, and it is what we agreed on, so it is payment
As far as God being able to create all of these things himself, yes, of course He can, but we still give Him these things as a form of payment for His continued love and favour. We don't generally call it payment, but from it still looks like that to me.