As I previously noted, the production cost of making the tooling means that much of a run needs to be pre-sold, or the person (if not the Manufacturing Fund) cannot hope to recover the cost of running these in the first place.
Forget about Edsel, Packard, etc....there are a lot more 1958 Edsels around today than any given year K-F product, and it is very possible that the molds for the lenses may have been scarfed up cheap at the Doehler-Jarvis bankruptcy auction some years ago. When people looked in the old storage areas at D-J, they found all kinds of Packard, Hudson, FoMoCo, etc stuff (including the tooling for the 72 inch wide Packard center grille c.1954). As for Packard, many of the owners will pay the premium to get proper quality reproduction items.
Lastly, if you look at the prices asked and the conditions presented, there is no wonder that the 1951 Frazers did not sell, regardless of the tail light condition, especially in today's economy.