John
I did not say your material cost on concrete was wrong. I am paying more then you are though. The material cost for most any local builder is going to be with in 4% of each other (which makes it fairly negligible). I don't know if you build in Alys Beach (I do not) but what is your out the door build cost run per square foot (Alys Beach standard finishes)? This seems to be what most customers are concerned with, the owner don't care what the concrete costs they only care about what the final product will cost.
Also, please use a little less attitude, I'm just stating that you saying local builders are colluding to raise construction costs is not accurate. Or, if it is, is not practiced by everyone.