I find these astronomical values claimed tend to come down when negotiations actually start and the player sees a step up. We saw it with Modric, for example, when he left.That assumes Dele's sale fee "plus some cash" would be enough.
Grealish is catergorically not up for sale. It would go into the £100m range, possibly higher. Wages would be similarly outrageous, he's got a nice deal at Villa, and we won't be able to improve it greatly.
Dele won't even fetch 50m in the current market.
And anyway I said someone like Grealish. The idea is to improve on Dele talent wise, maybe slightly (by paying more than we get from Dele) but get someone who is a better fit than Dele.
We simple need a number 10 that can create. Ndombele and Lo Celso seem incapable of playing together.