Perisici to Chelsea. Is someone who can cover the entire left wing and with 5 defenders he can play as a wingback in the role of Chilwell. Attacking still strong than Chilwell in my eyes.

Haaland to City would be nice. Especially to see how he copes in a team that plays so dominantly on possession, while Haaland is a bit more of a counter striker than a combination striker in my eyes.

The FC Barcelona backs. I honestly don’t get it.
Tagliafico is on the bench at Ajax and certainly does not have the qualities that FC Barcelona is looking for in a back when it comes to football and attacking. The only advantage is that he is relatively cheap and defensively a lot stronger than the average left back.
I don’t think Alex Sandro has reached a very high level at Juventus for 2 years. Nor will he be allowed to leave for an apple or an egg and do not think that he is a cheap boy in terms of salary. Doesn’t seem like the ideal back for FC Barcelona, ​​given his form/level of the past 2 years..
Alex Telles doesn’t have the level either. Offensively he is more than fine, defensively he is extremely weak in my eyes. Still a nice pace, but he doesn’t play everything at United either. Although I had the idea that he did get to play more in the last matches compared to Shaw (who was doing very well at the time).
Alfonso Pedraza plays quite a lot at Villareal as a back, while they also have Moreno (who plays more like LM) and Estupinan as well. Pretty handsome. Nice length for a back. Only advantage with him are his height and his nationality: Spanish. In terms of speed and footballing ability, I think he is a bit short for the level that FC Barcelona want to return to.
I think Raphaël Guerreiro is the only really good option in this list. Is defensively quite fierce, smaller in size and especially good offensively (also at the ball). Also played as LM or midfielder at the time, but will not be cheap either (unless he has an expiring contract of course).
I also noticed that Guerreiro has had quite a few (muscle) injuries in recent years.
I believe he has already missed 77 games for Dortmund since his arrival at Dortmund in 2016, mainly due to muscle injuries (and 1 ankle injury which I think I remember).

If they still want to get a replacement for Alba, also for the long term, and he should preferably be Spanish, I would rather go for Grimaldo or Gaya. Not cheap options either, but the above options will also (almost all) not be cheap.