I haven't actually used this guy's knives. But I've used cheap knives and I've cut myself on cheap, dull knives that don't hold their edge. And I've used moderately expensive knives. It's night and day. Cheap knives just aren't functionally equivalent.
The same can be said about coffee, chocolate and other fair trade stuff. Ground Maxwell coffee that comes in a can might be functionally equivalent to Intelligentsia beans at the task of "deliver caffeine in a hot liquid form", but that doesn't mean the Intelligentsia is more expensive just because rich people want to feel superior to people who drink Maxwell. It's in part because the Intelligentsia is less efficiently produced that it tastes better. And as far as I understand it, the Maxwell coffee is being produced in such a way that the true cost (to the workers, to the land) is not actually incorporated.