the use of a few choice words in the marketing/advertising spiel, such as "exotic, purposed-designed" and "very expensive isolating material" and "closed cell, cross-linked ethylene copolymer structure" ensures unknowing people think it is worth the silly asking price, and that the product has truly been made from these "purpose designed" components
Agreed, if the material really was purpose-designed then he'd have patented it and wouldn't mind explaining a little more about its unique properties. If not then its just so much BS, any other claims for the device have to be taken with a pinch of salt and the DIY route makes even more sense.
Regards,
JaS

