actually, I would say that of tec 27-38, the demand is much much less for 38 compared to previous issued copies (that is why those are generally quickly gobbled up into collections, and 38 sells much slower)
one reason we see so many copies for sale, is that we don't see very many of them sell at the asking prices .... don't get me wrong, it is a GREAT issue, but there are a ton of them, and presumably (based on the continual available supply) they are not in that much demand relative to the price and supply, when compared to most issues 27-37