Why would anyone look for a rational explanation of this pheonema. Collectors are a special bunch and value is often like art, in the eye of the beholder. You ask the same question about a 1943 coppper penny or 1933 twenty dollar gold piece. Why are they more valuable then the other similar coins with just a different date. Dare to say that there are billions of copper pennies out there yet people assign various values for various reasons to each of them. It is the same with bicycles, the danger is that what is hot today may not be tomorrow. Just because an RH commands a premium today does not mean that in 10 years it will stay on top. As a recovering vinyl record collector I can tell you that several records that were very collectible 10 or so years ago and commanded a premium are no longer desireable as the market and audience has changed. The same happens in all collectibles.
Ray Homiski
Elizabeth, NJ