I believe they sell replacement blades, but have not looked into it. The dental floss kept the blades from opening when they hit the target, so I just have to sharpen the leading edges of the blades when closed. Still feel pretty sharp, but I will run them through a sharpener before launch time.
I like the idea of replacing blades and reusing the head, but my last pack of Muzzy's was bought 6+ years ago and still have heads that I have not shot. Between Muzzleloading, the new 450 bushmaster and the limited time I get to spend in the woods, I am not worried about the cost of broadheads. If they are destroyed during a kill, I'll just buy more. Hope to get some real world test results this fall.