I agree - although I’d doubt if we’d get 50m for Gundogan.If we get 50 mil for Gundogan and spent 20 on Mooy (who I think can do just as good a job, and unlike Gundogan knows how to tackle ;-) then that's 30 mil left over which we can put towards a big time signing.
The other thing to note is, what is Mooys' value in the current market ? If it's much greater than 20 mil then that also means we obtain a valuable asset on the cheap.