I think this has potential.... I'd say mid $xx - low $xxx for reseller and mid $xxx - low/mid $x,xxx for the right enduser...
Also, with regards to the comment about inquiries without offers being worthless.... that is only true if you are a bad salesman.... honestly, nothing could be so far from the truth. I have sold quite a few domains this way... If they are interested, you can discuss. That doesn't mean you might not push them to make an offer, but don't throw away a lead because they don't initiate it with a price in mind...
Hope this helps!