Too much! Depends upon what they are looking for. Usually a CBC (complete blood count) is ordered. I had that and a thyroid test and about 3-4 other things to look at. If I had insurance with co-pay this would have run $20-$30, but having no insurance due to my husband being laid off, the bill was close to $300. Needless to say, I can't afford that, so another bad mark on my previous excellent credit rating. Most of the time the blood is collected at the Dr. Office and sent away to a lab, so there will be 2 bills--1 from Dr. And 1 from lab.