Think about this:
A model that is limited to 10 pieces, is it rare?
A model that is limited to 100 pieces, is it rare?
A model that is limited to 1000 pieces, is it rare?
If you have solid answer (either Rare, or not Rare) for any of the above questions, I believe that you are "biased" (IMHO).
Think about this again:
A model that is limited to 10 pieces and only 5 people want it, is it rare? <===let's call the watch model A
A model that is limited to 1,000 pieces but over 100,000 people want it, is it rare? <==let's call the watch model B
What do you think now?
Ok, let's think about the following:
Assume 95% of the 1,000 pieces of model B were sold out. Then 50 are still available in various ADs.
Now, there are 99,050 (=100,000 - 950) people out of the 100,000 people who wants to buy model B but did not get it yet.
Due to various reasons, the ADs may:
- keep the watch to the safe (and don't want to sell it now)
- unwilling to show it to walk-in
- fear to sell it to grey-dealer
- etc...
So, effectively, you "see" less than 50 available in the ADs...
Under such situation, do you think many people out of the 99,050 people would be able to see/buy the watch easily?
In short, I believe that "rarity" is a personal feeling...
if it happens that you are looking for an item for years but no luck in getting one, it is rare for you. (people in group A)
if it happens that you (due to various reasons) are able to find an "rare" item easily, it is not rare for you. (people in group B)
If you really want to define "rare" in absolute term, I would think that it depends on how many people are in group A and how many are in group B.
For 5970, I believe that it is "rare" in the "absolute" term (i.e. most people are in group A). There exists people in group B doesn't mean that ALL people are in group B or "5970 is not rare"... IMHO.
For me, I cannot / would not say something is NOT rare just because I can get it easily...
p.s.: All the numbers shown above are NOT the real numbers. It is just for illustration purpose.