Re: 1800 jobs
Always a conspiracy...
Yes, MS could end up paying more tax to Munich, but they'll claw back a lot in reliefs because they're moving into an urban regeneration project. Also, a location within the city, and close to the Technical University will be more beneficial for acquiring and retaining staff than being outside.
Microsoft are big enough to not give a shit what Munich uses for its IT. Had other cities followed suit, they'd be worrying, but it's telling that despite the huge licence cost savings no other major government has followed Munich's example. I'll bet they've been visiting and asking, though.
( Especially around the last week of September. These are, after all, local government officials ;) )