Where to get Pokemon Go Plus+ in Tokyo.

My husband is looking for a Pokemon Go Plus+ device, and so far we haven’t had any luck at the places that have been recommended.

We’ve checked the Pokemon center in Shibuya and Tokyo, the local Donkai stores, and most recently the Bic Camera stores near us. Every place has been sold out, so if anyone has any recommendations on other places to try, it’d be greatly appreciated. Another sub said it was discontinued but would it be available at any resale stores in Tokyo?