Thanks, very helpful! Let me first pull the starter and check the status quo. Maybe it's not bad at all. It hasn't failed a single time so far and pulls strong.
As far as local starter rebuild shops are concerned... this is Germany. We build crap cars that look shiny but are designed as a huge puzzle of "Believe-me-it-WILL-fail" parts - which are made to be replaced as a unit at the highest possible cost.
I assume that rebuilding a starter in my country means melting it and turning it into beer cans. Which isn't a bad thing at all but doesn't make your car run again.
So, I might get back at some point and ask for support from overseas