These knives in their own right are stronger than a knife really needs to be.
Keep in mind, most production knives (and most modern knives, especially folders) are made out of S30V, or similar stainless steels. They have great abrasion resistance, and good hardness. They are though, fairly brittle, don't be terribly surprised if you find yourself snapping that blade a lot easier than you might imagine.
The ZT300 series is a beast of a knife, I can't foresee an average person being able to break it, even the ZT200 (IMO not AS strong as the ZT300, but not far off) would be nearly impossible for most people to snap without a cheater bar. My XM-18 3.5" would be exceptionally hard to break (Not sure how CTS-XHP rates in the c-notch vs. say S30V). Striders are tough, heck if the Sebenza, which is quite a bit thinner than the others would be hard to break. Now the Sebenza, I'm sure you'd crack the upper 1/3rd of the blade clean off pretty easily, but beyond that it's pretty tough.
I have seen guys break these blades, they tend to have arms the size of footballs and lots of mass behind em. I'm a big guy, but I don't think I could take on these knives and break most of them.
One thing about the XM-18 I love is the spanto grind, the tip is incredibly beefy, it's designed to pry should it need to. It's a bit above your budget and darn hard to find, but it's a great contender.