Or even more to the point, why is numismatic luster?
Haven't we all at some stage lusted after that
rare expensive coin, hopelessly beyond our financial reach? If so then by definition you are a Numismatic Luster.
For the last six years I have been lusting after a coin struck from a specif die set at a specific
mint. All to no avail as no examples have come to market. I guess that makes me a
mint luster!