You are correct, the jetons shown there are not especially "rare', although the higher denom jetons from the Islands are tougher to find, and sell a bit higher then most shown there, as do the Niederbronn oversized jetons. What WOULD be rare is finding an obsolete 20ff Niederbronn jeton that is undrilled. I'd give up just about any jeton from my trade pile for 1 uncancelled example....
I have had probably 15 or so go through my collection in the past couple years (and had offers of many more), all colors, from both series, and all have been drilled. I wonder why someone bothered drilling ALL the "20s" but not nearly the same amount of the higher denoms, lower denoms, or plaques.