Coupled with that, is the extreme difficulty -- judging from the PMs I've received -- many have with their cultivation and relatively narrow temperature tolerances.
Ironically, Dalingtonia (which is cultivated similarly) took the reverse tack -- and was dirt cheap and available from any number of nurseries and hardware stores when I was a kid (sold as "The Cobra Plant" in a bag with a ball of sphagnum moss); though dealers have now been offering the same plants for upwards of 100.00, which were once 5.00 at best at any Orchard Supply Hardware . . .
TC has not benefited them too terribly well . . .