Ya know, you could probably find a better knife with a better sheath without spending much more. Then again, if you're convinced you're going to break or lose the knife, and you have one sheath to fit all three, that could be alright.
I don't think I would spend even that much just to sheath my Frost's, but then I've become a complete stickler for the flat-ground blade, so I'll likely not carry that knife anymore.
What I've found to be much more practical than a belt knife is a four-inch knife, with a flattish handle, that fits in the front pocket. The very top of the handle sticks out of my pocket, and I use a bit of nylon cord and a small snap-link to connect the pouch-sheath belt loop to the belt loop of my jeans. I wear it everywhere, and it doesn't hang up on things or get in the way of back-packs, pistol belts, vests, or other web gear.
Something like this, although mine is slightly longer and much pertier. This one's mighty pricey, though.