Personally I'm not a big fan of the Razer Phone 2. I would opt for the Samsungs if you want a premium phone with headphone jack.
I'm from Germany as well and luckily for you, by far the best deals in the middle-class and premium sector can currently be found for the Samsung phones. There are very attractive S9 and S10 bundles on the market right now. The S10e is bad value for money in my opinion at launch prices. It is noticeably worse than the S10, costs just 100€ less and you don't get the free Samsung earbuds that retail for 150€ and can easily be sold for 100€ on ebay.
You can get a new Samsung S10 for 36.99€ per month plus a one-time 69.95€ fee and a decent 7GB LTE contract here:
Took a look at it earlier myself and thought I might share it.