Who gives a fuck? Tyrone Mings moved for £15m from the Championship. Leeds bid £25m for Ben White and got rejected, Alfie Mawson £15m with no PL experience, Matty Cash £15m to Villa with no PL experience, Last year they bought Konsa with no experience in the PL for £12m. Bournemouth bought Chris Mepham with no experience for £12m.
There you go, there's an actual comparison of the going rate for a young, top championship defender, not just "Oh but a keeper we sold wasn't great that one time"
Fulham spent £6m on Michael Hector, who's got no top level experience, is 28 and is worse than Tosin, and that was before they got promoted!
When Everton tried to buy him last summer the papers were talking about £16m IIRC. 1 brilliant loan later and he's moved for under 10% of that.