[mrreality68]

Originally Posted by Leon

Demand increases value, rarity doesn't.
.

+1 agree and sometimes being rare also hurts. Something might be desirable but if it is to rare and does not come for sale/auction often then buyers do not know the value or perceived value and either may not bid or buy it or only go for a level that they are comfortable with which might be less then the seller wants to sell it for.
But it is as always worth what someone is willing to pay and what someone is willing to sell for