The Gigaset GS6 Pro is available starting at around €380, including from Amazon Germany or directly from the manufacturer.

This is a midrange phone despite saying "flagship" and the review criticizes its slow speed and not-so-good camera. It's nice that it has an SD slot and removable battery and wireless charging. 3.5mm audio jack is not mentioned. Review says you can use AphyOS (aphy.app) as an alternative to Google. No mention of Lineage or Graphene.

Overall this hardware is at roughly comparable to my 2023 Moto G Stylus 5G which cost half as much. At least it's not $1000 or anything like that though, and it does have some good points. The review is informative and worth reading if you think you might want a phone like this.