I don't think I'd go as far as paying agencies to locate it, heh. Maybe this is something I will have to look for one day when I fly to Japan and if I have an astronomical amount of luck I might find a loose cart.
I saw an auction for a CIB Iron Commando months ago on eBay (probably the worst place to see it, right?) It went into the mid 200's if I recall. It was a high profile seller so I'm sure tons of buyers got to see it was there before that was over.
There are a handful of titles I have a lot of trouble finding that shouldn't really be worth much anyway (e.g. Battle Formula for Famicom.) I'd assume it's not a valuable game but I have never found a copy for sale so far.
EDIT: Just looked it up and a Battle Formula was listed. Over $100 just for a cart. I'm not very thrilled about this. Why are Sunsoft games so bloody rare and expensive?