After capturing Lewandowski and Rode at the free transfer market, Bayern is likely to dominate Bundesilga for the years to come even if Kroos decide to leave this summer or next summer. Both Pizzaro and Van Buyten are also due this summer and I assume both players wont be given a contract extension.
Without spending a dollar in the transfer market so far, Bayern can definitely spend 40-50mil Euros every summer without selling any of our key players. But the question is will they spend any? As Hoeness has stated Bayern is not a selling club, so I would assume that we dont need further re-enforcement in both goalkeeper and striker/forward position.
in defence, with Badstuber due to back from injury next season, we might need to sign either an experienced worldclass central defender or a young talented one for backup. Or, we might need someone to cover up for Rafinha if Lahm remains playing as sole defensive midfielder.
In midfield, with aging and injury pron Ribery and Robben, we might need one young classy winger to back them up as Muller isnt the same type of player; Gotze's favor position is behind the striker; and Shaqiri showed lots of talent but unable to match either Ribery or Robben in terms of goals and assists .
What I would do is to try to extend Kroos' contract and let go of both Pizzaro and Van Buyten. Sign Ginter (10mil Euros) and Draxler (45mil Euros).