kei hin duals

I'm thinking about buying a set of kei hin duals complete with intake fuel pump and i think he's got the distributor too. They're pretty much like new. The engine it came from was imported from japan... late 80's 1.5. Since it came from japan would this be considered JDM or would they be the same as US models? Any idea what these would be worth? and what should I offer him for them, I don't want to pay through the nose.
Thanks for any info you can give.