always practice with what your hunting with..if you are not shooting the same broad head and arrow in practice, then yes you need to spend 1 on practicing, and ya got 2 left

I understand the logic of this, I really do, and I think there's wisdom in practicing ONLY with your exact hunting setup. However, the point is, you're probably only going to get one shot at an animal with a bow. I think you can practice with any number of arrows as long as when you're in the woods you have confidence that the arrow you have nocked is going to fly exactly right. Right now I have 8 arrows of basically the same make. I practice all summer with all 8 arrows and field tips. When it's time to switch to broadheads, I'll pick the 3 arrows that fly the best, and only shoot those three until hunting is over.

And yes, shooting into foam will dull your blades. I think you want to make sure you replace the blades so they are as sharp as possible before you hunt.

The point about confidence is legit. If you won't feel comfortable unless you shoot your broadhead into foam, then, by all means, shoot it until you have confidence that you can make the shot when it really counts. Not having confidence is the worst of all evils. You can replace or resharpen blades, so it's probably worth it to shoot those heads into the target.