Might be nostalgia, but looking back I believe that 90mil was well spent on him.
The two subsequent league wins primarily lay at his feet. And though we has won like 6 in a row up to that point, Napoli was the toughest opposition yet and his goals in terms of points tally.
He also scored the winner in the first game vs Inter during the Sarri season. And from what I remember the team would've probably collapsed mentally and Conte's Inter would've taken off had we lost that game.
All that is probably worth a 90 million transfer. The only shame is we didn't win the CL, but thats a crazy standard considering how long its been since the last CL victory and better teams which were about at that time.
Its just a shame that we never really saw that Napoli Higuain over here. I believe that would have been monstrous with the squad back then, but unfortunately Higuain was never the same guy after transferring. And its not an Allegri or defensive tactics thing, from the first second he was visibly overweight. Even when he trimmed down, performance wise he never reached the same heights as he had at Napoli. Bit of a weird one.
IMO, it was a culmination of a "win now" strategy which affected us in the long run. Higuain as a transfer in a vacuum, cost 90M, had zero resale value (as proven by termination of contract), affected the spending power into other areas (Khedira on his last legs, Pjanic, Matuidi, 20 year old Bentancur was our midfield in 17-18), and made us drift away from Dybala as the center of our "project". The positives are that he was a great player on the pitch more often than not, and that he bought into the team which helped us keep our winning going (you can argue in spite of him, you can argue because of him. But to me, we hit the jackpot with some players in 2011-2014, but we didnt do enough to build on it or to move away from them.
2014 we dont sell Vidal (we sell him a year later for less money, we get a free Khedira. Great player but 28 already and injury prone). We let a natural replacement in Nainggolan go to Roma (a year later we let another potentially great mid in Allan go to Napoli). We add depth in Pereyra who was good until injuries slowed him down a bit. We add Morata but its with a buyback. Evra was a good short term LB
2015 now Vidal leaves, along with Pirlo. Thats 2 top mids and leaders, with only Khedira who you can compare with them (although a notch below) incoming. Upfront we gift away Llorente, we gift away Tevez, Morata on his last 12 months. We get Mandzukic and Dybala, on paper a good partnership, but woth Morata gone, we would lack that 3rd striker of similar quality. We add wingbacks AS and Cuads, solid moves. But we dont add a 4th top mid and end up overusing Marchisio. We let go Coman after one year for no reason at all. We buy Zaza when we have Mandzu, Llorente, Morata, and we let go off Berardi (better player and more fitting profile)
2016, Pogba gone, we finally replace Pirlo (and Marchisio in hindsight) with Pjanic, but Pogba was the one to carry us offensively. We dont replace him at all. Instead we splash on a CF, thats a worse fit to Dybala than Mandzu. Similar level players went for less before and after that Higuain transfer. A waste and mismanagement of resources imo. Recent buys were Higuain (29), Mandzukic (29), Khedira (28), Benatia (29), and the following summer Matuidi (30), D. Costa (27), all starters in the 17-18 season before we went all in with Ronaldo.
These kind of signings are great if they are cheap like Khedira, Barza, Pirlo, Mandzu, Licht, even Benatia. You add instant quakity while not spending much, getting to spend your resources on a 22 year old Dybala, 24 year old Vidal or 24 year old Bonucci. Players who you can sell for 30-40M even after 5 years. But if majority of your budget goes into Higuain and Benatia who you will lose for free in 2 years time, Matuidi and D. Costa the following year, then eventually you end up going into a mercato needing to buy 4-5 starters. Then its imminent one of them will be a free Rabiot or Ramsey, so next summer you need 4-5 starters again. And again. And again. Look at Guardiola, all the money inthe world but where does he really spend it on? Look at the age of his best players when they were bought. Real Madrid too, what was the last 29 year old they splashed big bucks on? Its not a sustainable model not evwn for the richest clubs, let alone us. For that reason, i cant say Higuain was a great transfer. Not just Higuain, but a lot of our transfers since 2014