All of these are supposedly limited edition and the silver after market prices have been increasing.
I wouldn't recommend them as an investment though: their popularity is strongly tied to zombie theme movies and TV shows like The Walking Dead. Yes, The Walking Dead could well become a cult classic and live on in re-runs for many decades, but I think you also would also need to be concerned that counterfeits could dilute the market or destroy it outright.
Consider that when the U.S. Mint says something is limited mintage, it most definitely is and the dies are destroyed after production. What guarantees you that Zombucks master dies have been destroyed?
You can find the older Zombucks on Ebay and the very latest can be had at Zombucks.com.
According to that site, there will be ten in the series. While the Walker, Morgue Anne and the Zombuff are interesting, I'm not sure the Barber has quite the same appeal or even that many will understand why it is so named (Charles Barber designed the half dollar that is based on). That may be true for the rest of this series also, so the popularity could wane because of that.
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