I found a similar one (3.7V 100mAh) for 4.80€ (including taxes) in a small components shop in Berlin.
https://www.segor.de/#Q=LiPo3V7-100mAh
Right to Repair
Whether it be electronics, automobiles or medical equipment, the manufacturers should not be able to horde “oem” parts, render your stuff useless if you repair it with aftermarket parts, or hide schematics of their products.
Summary video by Marques Brownlee
Great channel covering and advocating right to repair, Lewis Rossman
I don't think there are many electronics stores around anymore. I usually either pick something from Aliexpress that has less shipping cost, or buy online: eckstein-shop.de reichelt.de az-delivery.de berrybase.de (But Germany probably doesn't count as West Europe...)
They closed most of their stores, there are only 4 stores left in Germany. And back in the day they used to be pricey, I wouldn't order online unless that has changed in the last years.