No Bayern own it but they allow 1860 to play in their stadium.In a few years time they'll pay off all the stadium debt and will be making revenue probably even more than the likes of Madrid and Barca..Yes you are right about ticket prices as they generally tend to keep it low as they care about the fans as well..IIRC Bayern makes about 70-75m euros matchday revenue every season.And thats not bad but obviously much lesser than the English and Spanish clubs.
- - - Updated - - -
And to answer your question they make so much money mainly from commercial revenue..They rake in almost 180-200m commercial revenue every season through loads of sponsorship deals ,merchandizing etc.