As others have said, the funds aren't going to be re-invested, 10 years of experience tells us this, so any plans of 'well if we receive X, then we can spend X on player Y and player Z' are fantasy-land, regular football club notions. If he goes for £30m to a club like Everton, then all it does is confirm even further how incompetent our owner and decision-makers are.
That said, we can't really be too displeased if he leaves for circa £50m to a CL-caliber club if Jamaal wants to go to a more ambitious club - I would support his decision. Reminiscent of José Enrique to Liverpool, I never held a grudge against him because he said he wanted to go to a more ambitious cub. I don't want to see him leave, but I wouldn't blame him at all. And if Rafa then goes, that's me done with NUFC anyway until MA dies, so I don't care.