Disclaimer... this is not my listing, I very rarely sell anything (I'm too lazy for that)
With that said, I see lots of reasons why someone would list such a thing:
Low barriers to entry - I don't think
eBay charges anyone to list stuff anymore. Therefore he only has a cost if it sells (being
eBay, that cost will be high, but obviously he already factored that into the price)
What it's worth - I have yet to see a Kelly blue book for used casino tokens and therefore I'm certain that "what it's worth", like most other "collectibles", is purely defined by what someone is "willing and able" to pay. There may be some "usual and customary" prices on this forum, but in the scope of the broader market (like
eBay) we are certainly talking about thinly traded items with minimal pricing availability.
I would also add in the common misconception that people attribute value to scarcity (ignoring demand). For example if you have a Yugo, it may be scarce, but it has no value (because no one want's it).
Although I don't think it's true for this item, people do have a tendency to overvalue things they own vs. what other people own. For example if it's my chip it might be worth $2 to you but once that exact same chip is yours, it's worth $5 to you. I think I read about this cognitive bias in one of the Freakanomics books but it might have been in one of Dan Ariely's books, or even something else (I read a lot of books).
But mostly I think they have tried to sell it other places, with little success, and now are turning to the broad
eBay user base trying to find the "one collector" who makes an emotional decision (i.e. falls in love with it) and is willing to pay whatever the price to have it. Collectors are generally not rational actors (put away your pitchforks, you know I'm right).
Personal Anecdote: A friend of mine used to have a mall Kiosk where he sold and Traded Pokemon cards (and goods). My brother, a collector (mostly numismatics), against my suggestions, purchased a number of "collectable" Pokemons from my friend. Years later, when the printed cardboard no longer had a resale value, he started bitchin' to me about it - I made short work of dissecting his stupidity and haven't had to listen to that nonsense since
Alternatively, I could be over analizing it - The lister could just be operating under the P.T. Barnum maxim of "There's a sucker born every minute" (which is mostly true) - Anyone wanna buy some Pokemon cards
P.S. - I did have a small financial interest in the Pokemon Kiosk.