A turnaround in my childrens' attitude

I had been having a really hard time with my boys having a bad attitude when told to do their chores. I have no idea what happened but their negativity was really starting to affect me and I didn't want it to rub off on their little sister. I prayed and prayed. This was serious because peoples moods really affect my mood and I don't put off a bad attitude when I'm doing chores around the house. It actually makes me really happy to bless my family in that way and the boys know that. So what was I to do? Well, something kind of just came to me so I decided to give it a try. My boys are always wanting an allowance but we don't give them one. I think we might go broke if we had to pay them for all the chores that they do. So I decided to make them fake money on little post-it notes and I customized the money just for them. My son Beau, earns BEAU BUCKS and my son Bakari earns KARI DOLLARS. Anyhoo, when they do a chore wwith a good attitude and/or I catch them doing something that I feel is exceptional, then I pay them with their fake money. After they've earned ten BEAU BUCKS or KARI DOLLARS then they can turn them in to me for a prize out of the prize box which we all made and decorated one weekend. The prizes are usually candy bars since I don't allow them to have those often. After they've turned in their ten fake dollars they start all over collecting them again. This system really has blessed our family because now they get up earlier every morning and cheerfully get started with their chores and begging me for more chores. And at the end of the week, how much money have I lost? Only about $1.00 for the price of two candy bars and that treat makes them so happy and I'm one happy momma.