Interesting. I like the idea of switching blades to customize the rig to fit your need.
But the first question is: Why is the hub so big? If it was smaller the entire unit would be more compact, possibly lighter. As it is the large hub makes the unit seem quite bulky. I don't want it if I can't carry it conveniently. The fact of human behavior is that if it is a pain to tote around I'm going to find some excuse to leave it behind and it won't be there when I need it.
As a novelty, to a collector, it might be well worth every cent. But to a person seeking a tool for use in the field or EDC it falls short.
I have to note that I have seen alternative blades for a Leatherman Wave. Some of these may be available through the manufacturer or outside vendor. I have been told, but have never sen, similar alternative tools for SOG multi-tools.