But do they also have reasonable prices? When Telekom finally put fiber at our street their offers were so stupid, that basically everybody kept cable.

For starters they limit upload for no reason. Then they capped at 1 GB and wanted like 130€ for that. At the time I had the very same on cable for only 45 € or such, so I basically told them "give me prices and speed like in Switzerland and you have a deal". The sales guy only asked me "why do you want that much upload?". Like, because there's no reason for you to limit it at all, only greed.