It will not be very difficult for Real Madrid to get Bellingham if they wish to get him. It is not always a problem for Madrid to get any player they want before they have the money and again they cannot be seen as the biggest club in Europe which every player will like to play in for prestige and fame. Bellingham himself will be happy to play on the big stage of Madrid.
Dortmund always creates its best players as happened to Erling Haaland who comes from Dortmund is also the best attacking player for now and next from Dortmund produces another good attacking player named Jude Bellingham and If Real Madrid want to have him then they have to move quickly so that when the transfer market opens at the beginning of the year he will not be bought by another club.
Dortmund now is more of a profit oriented business, they are mainly open to selling every good talents for huge profit rather than keeping and developing them for the future of the club. When I think about the level of the squad they would have now if they hadnt sold out their talented players, I see a team dominating the whole of Europe at every level but that is not the case because they prefer to make profits from transfer market.