How much should RN make if she circulates, scrubs, and sometimes assist?

I came into the OR in June 2009 to work in CVOR (Cardiovascular) as an RN. We do open heart surgery (valves, ect) and we do a lot of Thoracic cases (lobectomies, pneumo, ect). I was hired as a circulator, and for 6 months thats what I was trained to do. As soon as the 6 months were up, I was asked by a Doctor if I would learn how to scrub for him and to be his primary scrub. During the next 6 months I would rotate circulating and scrubbing wherever I was needed. In the last 2 months of the year I was hired, I was asked if I would learn how to scrub a second doctor. I will have to say that learning how to scrub a heart surgery is one of the hardest jobs I have ever done, to learn a second doctors routine is even harder. With that said, in the last month or two I have been not only scrubbing but assisting doctors until the vein harvester comes up to the chest. With all that said, I have not yet received a raise for any of that yet. My supervisor told me that the hospital does not compensate for any of that. I was just wondering if my hospital was the only one that does not compensate for going from RN circulator, to RN scrub, and not only for that but for several doctors. I was considering looking at what other hospitals make for each position so that I could take this to Human Resources for them to consider different pay options. Thanks so much.