If we want this lad then we go for him first, regardless of the Sane situation and Bayern.
I don't believe Bayern for a second when they talk about having only 80m to spend this window - they have Ribery and Robben off the books for a start, and their directors are mostly a bunch of lying gits as proven in court outside of football, plus they sling mud at us from afar whilst perverting their own league to an almost uncompetative standard.
If he goes elsewhere we move on to plan B and Sane's price remains high. He's a great talent and would strengthen a Champions League rival, plus has plenty oftime to develop into an even better player. If he wants Germany for personal or family reasons then he can work with the club to find a solution and for clarity - Kun does it whilst having kids half way around the world and the club have proven ther flexibility with David Silva.
Bayern can either cough up or prove themselves liars again.