Once the production run is over, there may be a nice market for any extras. I'm planning on this being basically a one-time build, like Lionel's BTO process. 
What I'll probably do is make the PCB files and the BOM available if someone feels the need to have one after the initial run is complete. Given the need to buy all the stuff like the enclosures, etc. in bulk to insure having them, I can't really afford to be stuck with a bunch of extra units.
