It's a lot easier to learn German from another American than from a German who barely speaks English
Disagree with that in a lot of ways. Comforting perhaps when you start, but once your brain realigns, it is in fact "easier" to learn (as in make the most rapid progress) using only target language. Immersion, as serena says. It's not the same if you revert to English every minute or two.
Good idea to get out and build clients but, as per first post, you need to say what customers get for their 150 Eur.