As for manners, classical music, heros and such - not extinct but just a
bit rare.  However, turning to the shell world on extinction we should
remember that Strombus listeri was known from only one specimen for quite
some time.  When first rediscovered the price reflected this.  Now it is
maybe a bit too available.  Could it be over-fished and become rare
again?
 
The Pleurotomaridae or slit-shells were, like the coelocanth, also
"extinct" until the mid 19th century and were then "discovered" and still
very rare for over 100 years.  They are certainly no bargain now but many
species are readily available.  As fishermen go further afield and deeper
in their efforts for the big catch we will probably continue to find new
species as well as rare or extinct ones.  Like Mark's ferrets, some
species hide or are reclusive (not certain that is even a word).  The
Cypraea aurantium is a good case in point, not common, certainly, but not
rare - it just hides (or so I have been told - the only one I am familiar
with just sits there looking dead but great in my cabinet).  Of course,
at the same time we are certain to see many species disappear due to
habitat destruction (like many snails in Hawaii) and other human induced
problems.
 
This all leads to one conclusion - as an investment shells are probably
not the best as the market could go either way.  They are great to look
at but not a great addition to your portfolio.  I have a couple of shell
catalogs from the early 1970s (Eisenberg in New York) and while most
prices have gone up - it has not been level with inflation.  Some species
remain about the same.  A Tibia fusus was available in the 1970s for just
about the same price you will find one today.  Of course, back then you
could get a 4 inch Cypraea cervus for $5.00!  I think it was somewhere
around 1969 or 1970 when I saw my first Conus gloriamaris - it was only
about 60mm and was offered to me for $2,500!  At the time I thought the
guy was telling a big one about its rarity and value.  Sure glad I was
broke as usual and unable as well as unwilling to "invest."  I'll bet
every dealer has been stuck with shells bought at a high price only to
see them offered the following month or so at a much, much lower price.
 
Well, that was all a bit pompous from a rank amateur.  But I had some
real work to do and this seemed such a pleasant alternative.
 
Until the next meandering sermon, see ya,
 
Tom Eichhorst in New Mexico