I think they really should go for talent now, instead of more competitive pieces to complete the team, who end up expensive as well because of wages (i.e. Witsel).
For example, Dembele to me is the next big thing in world football after Neymar - Dybala. I was astonished when I saw him playing for Dortmund. He not only has crazy dribbling skills; he can use both feet apparently equally (HUGE for any forward), has good decision making, teamwork, decent vision, passing. He's not as raw as it could seem for a 19 yr old kid.
Even though he doesn't really fit our current formation, and we desperately need a good midfielder, I'd be glad if Juve could go crazy on him offering 40 or 50M to Dortmund, and mainly, try to lure the player offering wages Dortmund can't even dream of.
If it doesn't work, go for the best young midfielder there is - Tielemans, Bazoer, Dahoud, Tolisso (or Colisso, whatever is his name) or any less hyped but equally great talent.
Make sure we get Berardi, and we will be set for the real transition season - 2017/2018, where I really think will be the last year of our 3 CBs together + Buffon.
In 2 years, Buffon and Barza will possibly retire, Chiellini will possibly be relegated to the bench and Bonucci will be our remaining stalwart. It will be huge. While this doesn't happen, we have to make sure we already have the foundations of the new columns and that they get at least 1 year of transition on a bigger role.
Dream players in september 2018: 433 or 4231
CMs: Marchisio, Khedira, Lemina, Bazoer or stg
LWs: Dembele, Pjaca
RWs: Berardi, Cuadrado
AMs/Ss: Dybala, Pjanic
CFs: Higuain, Kean
Ideally we need more Italian players, but Marotta already let understand that "Italianization" won't go before quality, so...