Reports in the British media on Monday morning suggested United are prepared to pay the Germany international £250,000 a week if he moves to Old Trafford.
Kroos would treble his wages if he moved to United, who would reportedly be prepared to pay the German giants £30m for his services.
The midfielder's contract ends in June next year but Bayern have as yet been unable to agree a new deal with the 24-year-old.
Bayern's honorary president Beckenbauer told Sky Germany: "He shouldn't raise the stakes too high.
"Bayern will make an effort to keep him, but when the demands are too high, a decision will be made.
"There is no player who you have to give everything to keep. Everyone is replaceable."
Bayern's director of sport Matthias Sammer says the European champions are keen to keep the attacking midfielder.
"We know that he is a very good player and we want to continue with Kroos," said Sammer. "Everyone at the club sees it that way."
@muforever001> Yes City and Chelsea haven't earned their money, rather their benefactors drop change into their begging bowls. However by doing so they have made the PL very competitive. Without them United would be the dominant force and while that sounds great as a United fan, it would make for a boring predictable league.- Synergy
Lastly United could have & should have taken the same stance with Rooney, that Bayern are with Kroos. Bayern are risking Kroos leaving for other clubs willing to pay higher wages as United would have to have risked with Rooney. United chickened out coz they no longer have SAF and are worried of losing Rooney.