Average Roof Cost per Square Foot?

[Timur Medaric]

I'm trying to get an idea of what Roof's cost to Replace/Repair? I figured as many answers as possible would help put it in perspective. What is a good "Rule of Thumb" to go by in pricing roofs? Assuming that the roof is fairly standard with no intense angles. Also, I am in Dallas/Fort Worth if that is of any help with regard to pricing variances?