As this project appears to be fairly unknown in the fediverse still, I’d like to use this opportunity to advertise Flohmarkt. This Fediverse equivalent of Facebook Marketplace already has some instances up and running - see here: https://codeberg.org/flohmarkt/flohmarkt/wiki/flohmarkt-instances
Pole here.
A federated MediaMarkt. Or at least something with shopping, selling something. Definitely a German product. Should be a quality one, but I would name my instance (or a national one) differently, perhaps in a local language.
There is no point in making worldwide Flohmarkt instances (same for Mobilizon), so, the naming should be less a problem than you expect