Just came across this thread searching for something else...
But I'll add one more to the "we used Wayan" brigade. We used him in spring 2004 for a total of 7 days. I recall that his day-rate did come down when we added more days, but I think we paid about $33/day.
Wayan seemed to know every road, tourist attraction and person in the country. He even arranged to have our laundry done, and picked it up for us the next day. He had no problems leaving as early in the morning as we wanted (including a very early pick-up to see the sunrise on Mt. Batur).