If this was Higuain of 5 or so years ago then I'd be all over this. We've proved in the past that going for these types of strikers (ones that are past it like Eto'o, Falcao, Pato and even Torres and Shechenko) doesn't work out so well for us. They might pop up for an important goal here and there, but for the most part they didn't live up to expectations or were never long term prospects.
I honestly think we should give Morata another chance. He does have some talent, and if Sarri can tap into that he could start banging in the goals on a regular basis. He's still young enough that we can build our attack around him. If Hazard stays and we can upgrade our right side it's only going to benefit Morata. The only reason to get Higuain in would be to play back up to Morata and help him develop even more, but we already have a player like that in Giroud. Our strike force (Morata, Giroud, Bats) isn't actually that bad.