Dybala would never accept Inter. Even if they give him 15 mils a year, there are no guarantees they will challenge for anything in ... the remainder of his CAREER. He has been to 2 CL finals already and anything other than a team with a serious chance of winning it is a no-go for him.
PSG, Real M, Barcelona, City and maybe Liverpool are the realistic transfer options. I'd still swap him for Messi - would love to see CR7-LM10 partnership in a 4-4-2. Chiesa and Bernardeschi on the wings...