Too hard on disipline?

So if you read my last post you know how we handled the paint on the porch circumstance. I feel like we did the right thing. Our kids earn money each week by completing their homework packets on time. We give them 1$ each. If they don't do their packets, they owe us 2$. Good incentive to get it done. (Earning money for themselves is a whole other post I will get to another time.) Anyways, Chris had just given them all their dollar before we went to Ace to get some paint remover. Grady and Taylor were mad about having to spend all of their money on something stupid and they were mad at us. I was mad at them for wiping their little hands full of paint all over my porch, little stinkers. Again, I feel like we did the right thing, (do you sense me trying to convince myself?) When we got home we were watching the Olympics and Grady said, in his ever so tearful voice, "First you give me money and then you make me spend it." Sniffle, Sniffle. I tell ya, that kid knows how to get to me, I felt so bad after he said that and I still feel bad. I still feel like we did the right thing though. He just knows how to push my buttons, he is a smart little boy. I hope that this whole ordeal teaches them a lesson about doing the right thing. I can just hear them in my mind laughing and giggling while they are wiping the paint on the porch...heaven forbid they get some paper towel or something....little kids....I tell ya!