I estimate around 30-40 hours for my typical bows. But this usually includes straightening, recurves, skins/stain, grip, tip overlays, string, sealer, etc. So I guess most of that time is spent on the finish work. But like Clint said, if I'm going to invest my time into something, I go all out.
Now arrows, I spend another 10-15 hours on a set of 4-6 dogwood's