I find typically I range from 1 finished image a week to 3 on average. 2 so far this week, one for here and one for 'rotica. I find it best if I let an image sit for a day or two when I think its done and then go back and give it a good look over again. If I am still happy then it's time to up it. My rendertimes are between 1 to 5 hrs typical (in C4D), the longest was a day each for four layers to be composited in the final render (a la Flak).

Pass no temptation lightly by, for one never knows when it may pass again!