Absolutely you were not too tough on him. I actually would have made him pay more than you did without a chance of earning the money back. At eight years hold, he KNEW what he was doing so I think he is old enough for the consequences. He might be mad about it but in his heart of hearts he will know that you are being totally fair and I would be willing to bet that you will see a great improvement in his behaviour. Kids are very tuned into what is fair and you were! Stick to your guns, I think you did the right thing.