What's the highest commission you have seen?

With the slow down in the Phoenix and surrounding areas market we have been seeing some interesting commission offerings. For example one new builder locally was offering sixteen percent on a spec home. Others are averaging anywhere from three percent to eight percent. I was just curiou what the highest you may have seen in your area is and what your opinion is of  the average. Thanks in advance and I see a sale in your future and you should too.