After the transfer window closed, Transfermarkt compiled the squad-building costs of the 18 Bundesliga teams. Squad-building cost refers to the transfer fees spent by a team to assemble its current squad.

Bayern Munich have the highest squad-building cost in the Bundesliga at €538 million. Bayer Leverkusen rank second at €478 million, not far behind Bayern, while Borussia Dortmund rank third. Schalke's squad-building cost is only €9.65 million, ranking second from bottom.
Squad-building costs of the 18 Bundesliga teams
1-Bayern Munich, €538.3 million
2-Bayer Leverkusen, €478.25 million
3-Borussia Dortmund, €376.4 million
4-RB Leipzig, €328.6 million
5-Stuttgart, €186.3 million
6-Hoffenheim, €159.25 million
7-Eintracht Frankfurt, €141.6 million
8-Freiburg, €101.3 million
9-Augsburg, €50.7 million
9-Cologne, €50.7 million
11-Borussia Monchengladbach, €49.4 million
12-Hamburg, €48.05 million
13-Union Berlin, €46.55 million
14-Mainz, €33.85 million
15-Werder Bremen, €28.38 million
16-Elversberg, €16.57 million
17-Schalke, €9.65 million
18-Paderborn, €9.45 million