I couldn’t agree with you more on that.
Our older one, when asks for stuff, almost always do it in the form of a wish. The other day we were driving somewhere during evening time and she looked at a bright star in the horizon and said ..mom, dad if I look at the star and wish for something, will it come true. Wife told her that you should do it in form of Dua and ask Allah Miyan for what you want. I lovingly said that ok why dont you wish for it and say inshallah at the end. We forced her to say it out loud although she was sure that the wish is not going to come true if she loudly speaks it. Turned out that she wanted a DS (handheld nintendo :D).
But somehow she is still trying to figure out the concept of how the money is earned and how it is spent. One day, we have a family day at my work place and we had some clowns and music band. I brought her there and till very recently, she was surprised that daddy get paid to watch clowns doing tricks at work (she does not know how true that is at so many different levels :D).
Anyhoo, if we ever tell her that baby this thing or that thing costs money, she gets very emotional and runs to her room and takes out all her cash that she saved so far (I think she has about $120.00 in her wallet right now) and insists that we take the money cause she cant tolerate the concept that her mom and dad dont have money.
She watches free kids shows using on demand feature of our cable and she knows how to do that. One day she went to some other menu and saw the new chipmunk movie. Thinking that its free, she hit the play button. Then she very excitingly ran to me to tell me that she found the chipmunk movie on demand. When I told her (laughingly) that she just rented a $4.99 movie, she literally started shaking and burst in tears saying sorry dad, I did not mean to, could you please return the movie dad, please. I dont want to waste your money.
I cannot tell you how hard it was for me to hold my tears at that time. I hugged her and told her not to worry and Allah Miyan gave daddy enough money to keep his kids happy (alhamdulillah). She still insisted that she is going to pay me for that. I asked her to pay me a quarter that she did 
I am sorry, I did not want to write my life story here but Muzna you can imagine. We just cannot stop talking about our kids, its so difficult.