I do absolutely love Haaland but given the choice I'd pick Mbappe who is just more complete. However, I've always seen it as impossible that he'd join Barca so never given it much thought.
I cannot see Real not prioritising him either. I also think spending big on Haaland looks very risky given his undoubtedly worrying injury record.
I mean considering all the 100M+ transfers that have happened in the past few years, and most of them turned out to be even bigger flops, 75M ain't that much. Of course there's the wage and signing bonus and dealing with Raiola, but still. If Haaland does turn out to be the star or at least the co-star of the next decade, it will be money well spent for whoever gets him right now because of that release clause.
I don't see him staying at one club for more than 5 years though, think he'll be like a mini Ibra, playing for at least 6-8 clubs when all is said and done in his career. The next club being his 5th one, also counting both Norwegian clubs before Salzburg. Yet, if he stays fit and firing, I see his next club actually selling him for 100M+ in 4-5 years, thus still making a profit on him. I see him coming to Spain this summer, rumoured is he wants to come and play in La Liga at this stage in his career. And then he will end up playing in the PL one day too, probably at City because of his father's legacy there. So maybe come to Barca right now, with Mbappe to Madrid he helps revive La Liga and El Clasico as the biggest derby in the world. Ultimately helping us get 2-3 La Liga titles and hopefully the same amount of CL trophies in his time here, then we sell him to City for like 120-150M in 2026 or 2027. I'd be pretty good with that honestly.