If I were them I would get rid of Benzema right now when he can still provide a tad bit and get a super young talent, like Haaland is talked for Chelsea and I believe Real could try to chase him down as well, 150 million is a ton of cash but if they could manage to get it, they would be unstoppable for a few more years easily.
Erling Haaland and Kylian Mbappe are indeed good options for Real Madrid, but to be able to get one of the two is not an easy matter. Both players have a very high transfer price and both are being targeted by many big clubs. Besides that, as the new coach replacing Zidane, Carlo Ancelotti must have had his own list. If these two players are included in Ancelotti's list, it is likely that Real Madrid will insist on pursuing them. But if it's not on Ancelotti's list, then I think Ancelotti already has other good options.
In any case, Real Madrid will continue to hunt for these players and try to buy them, even though Erling Haaland and Kylian Mbappe are on Ancelotti's list, even though they are not on this list, because this is already a matter of the club's prestige and a powerful object for subsequent marketing and future income. And I don't think Ancelotti will give up working with Haaland and Mbappe for the players on his list. Another question is that the simultaneous purchase of these forwards can hardly be discussed, even for a club like Real Madrid, especially in the current financial realities.