This question makes little sense. I's like asking how much is a pound of steak, without specifying what cut, and where you are getting it.
It all depends on how you use them. I think I am loosing out if I get less than 5-6 cents per SPG point (divide by 3 for marriot points), but my best redemption was a hair under 11 cents per spg point. If I dont get this value I dont use the point. Right now I have a pretty good cushion of points to spend (after conversions figure about 700k spg equivalent). There are other uses for points were you might not get half a cent per points.