The 34 figures in the Second Series are usually harder-to-find because Marx made a lot less of them than they did of the First Series figures. But not all of the "New" Disneykins are worth big bucks.
All of the First Series figures (and some Second series ones) were produced for over ten years (from 1961 to the early 1970s). A number of the "New" Disneykins were produced for only about a year (from 1961 to 1962) which accounts for their scarcity in the secondary market. The "New" Disneykins brand name was only in use for about a year as well. Combine that scarcity with the fragility of some of the figures, along with the demand, and you get the high prices for the rarest "New" Disneykins. Soon after their introduction some of the figures were expanded into their own separate Disneykin lines, like the Pinocchio Series, Ludwig Von Drake, Babes in Toyland Series, and Lady & the Tramp Series. In most cases, the more valuable ones are the figures that were only available for a short time.