What other meaningful way is there to look at it except him being worth 47 million based on ability, performance, or if you want to go even further... achievement given he just won the world cup. Those are the things that actually matter whereas "not a price we should pay an Eredivisie side" is completely arbitrary. It's just not a metric in any way shape or form, it's based on the vagaries of a gut feeling on an entire league and had it been followed we wouldn't have got a top player.
Even if we do go down that route I'd say it's a little insulting to a side like Ajax. They've got eyes like we have even if they are Dutch. If they have a talent they believe is ready for a club of our stature under long term contract, they're not selling for 25 million in the year 2022. It seems a fairly normal price to be honest, Ajax are a strong club, it's a bit different to buying from Fortuna Sittard. So I don't think there can be a blanket idea about the Eredivisie. Depends on the club and quality of player like everywhere else.
I think Antony is an example of where we were a little too keen to press home the manager's idea at any cost. That was a lot more expensive and therefore entailed too much risk for the profile of the player, plus most importantly he has under delivered on it so far.