The rumour indeed Liverpool will buy at least one midfielder player this January so some of names appears including De Jong but the chances is very slim considering De Jong transfer fee is very high approximately 60 millions Euro and probably Liverpool will buy another players who had lowet price because Liverpool main target is Dortmund player Jude Bellingham and even Liverpool are willing to pay Bellingham transfer with fantastic price on summer 2023 and for this January Liverpool has some options to buy besides De Jong Liverpool also linked to Betis player Guido Rodriguez and to get him Liverpool only have to pay 30 millions Euro
Liverpool if they want to buy a new midfielder, they have to consider the position of the player and consider the costs they have to pay because if they only buy players without looking at those two factors, they will lose, the transfer market still looks very far at the beginning of the year so maybe Livepool can get even better players for a fairly cheap price.
I agree with you, if you buy a new midfielder, you automatically have to sell one midfielder or one player so that Liverpool's finances don't swell because in terms of the players I see the quality is the same, but what I saw earlier was the Liverpool match with Manchester City.