I've been trying shorten my time. My mentor has been doin this for quite a while, and he can get one out in pretty short order.
Of course, he doesn't mess around with some of the things I experiment with, like attempting SEO, trying out new lists, keeping recip tables unique, adding as much unique text to new sites as possible, etc... but he sells better'n me, so... eh.
All told, 3-5 hours now, I think. But I think I can continue to shave off minutes here and there as I refine my technique.