To me, rare is an over used term. I think in order to determine rarity that you need to have some idea of how many were made and /or how many may still exist. A couple for instances: the large John Deere cut-out wrench is rare. Only a handful are known of the 100(I think) that were made. The miniature Wilton bullet vise I posted is also rare, as only 7 were made.
The Reechet, on the other hand, was a manufactured item that probably had thousands made. How many survived is of course unknown. I would call it uncommon, but not rare. But that's just me, and probably not indicative of how others may feel.
The value of an item is determined by how many are available along with how many people want that item. To determine that value is the hard part.
Since I haven't had anyone "breaking down my door" trying to buy my Reechet for a ridiculous sum of money I would say that they aren't worth a whole lot nor are they rare.
For this kind of item I fall back on the idea "that it is worth whatever you and I agree on,at this particular time,on this particular day". That, of course, could change with a different seller, a different buyer, and a different day.
Just my ideas.
Mike