The expensive broadhead that I have seen bounce off rocks, cut a field point from another arrow nearly in half, and get shot into hard walls and other man-made stone and metal objects, is the 300 Xtreem three blade broadhead. the only damage I have ever seen to the broadhead was some flattening of an edge on one of the blades. Those are incredible broadheads, but my understanding is that they are no longer being made after a short production period. That is a shame, because even though they sold for $25 each, a dozen of them would last a lifetime if they were not lost. They were made using an MIM molding process that produces a very strong, uniform metal product. The 300 Xtreem may be the strongest and most durable broadhead ever made. But trying to get your hands on some will be next to impossible, as guys like me will never part with the few we have.
I also have a dozen and a half of the ABS Ashby broadheads that are even more expensive than the 300 Xtreems. I do not have much experience with shooting the Ashbys into hard objects, so I cannot speak to their durability in those circumstances. They are very well made and appear to be "hell for stout", but looks can be deceiving. I do know that some of the early Ashbys had some issues with production quality, but I also understand that those issues (mainly heat treatment I think) have been favorably resolved. I just can't bring myself to voluntarily shoot a $30 broadhead into a rock or a brick wall. Maybe the guys at ABS would be willing to do that as a demonstration. I do know that the Ashbys are sharper than any other broadhead I have ever seen and that they hold an edge very well.
Allan