ThePokmonGo Plus peripheral is not launching until the end of July, but it's already sold out on most online retailers in the US.
But there's one website where you can still find it if you're willing to spend a lot of money: thePokmonwearable is available on eBay for prices starting at $100.
Sellers even offer the Pokemon Go Plus accessory for as much as $475, when its initial price is only $35.
This Blutetooth accessory allows fans to play Pokemon Go without using their smartphone, through notifications alerting the player when a Pokemon is nearby.
Pokemon Go launched last week and already is a massive success, shooting straight to No.1 in the US and outperforming hits such as Clash of Clans and Candy Crush. App Annie even claims that Nintendo's game will make $1bn a year.
The title should come to the UK in just a few days, recent reports suggest.