So I did find a company in Munich that did the besichtigung and are offering by far the best price. They have nice reviews as well.
Will post an update here once the deed is done and hopefully some good advertisement for them. :)
It is time for me to renew my Blaue Karte and I finally got an appointment in KVR Munich for October.
One thing they mentioned in the e-mail confirming the appointment is that it would be nice if I can get the B1 Zertifikat so that I go directly to Niederlassungserlaubnis and not again with Blaue Karte. Maybe they want to avoid more work in the future.
I have done German classes until level B2 and I can speak/read reasonably well, so I don't think I need much study in order pass in the test.
Now the question is where could I do the B1 test before 13.10? I have looked on Goethe and some other schools in Munich and they all seem to have the test only for later than October. I will start also looking for Goethe in another cities near Munich, but the closer the better.