We never needed a new striker. Just fix the rest of the team, sign midfielders, wingers, fullbacks, CBs, whatever is the biggest need and Kean and Milik and Morata and Matri and Quagliarella will do just fine for the time being.
Build a team first, because so far there has been absolutely no difference whoever plays upfront. Vlahović certainly didn't make a difference for that money. When defense, midfield and wings started playing better so did the attack. Attack relies on the other parts of the team, not vice-versa