Bayern Munich sporting director Hasan Salihamidzic admits they're stunned by the spending of Chelsea in January.
The Blues spent near €400m over the four weeks of the winter market.
Salihamidzic told BILD: "This sounds crazy.
"For us, such amounts are unimaginable. When we have the opportunity to get a top player in the Bundesliga, we first need to decide how we will make up for the transfer costs.
"Bayern simply cannot make up for more than 600 million euros. We know we cannot compete financially with clubs like Chelsea.
"But we know how attractive Bayern are for football players because of their playing style, success, history and atmosphere at the club."