Grealy agree with you, great post !I dont think we will buy anyone. There is a reason why we brought back Denis and also add Andre Gomes. We will 100% give them one more year to prove they are capable of playing for Barca. Only players better for our CM spot are Coutinho and Verrati but wont come surely next year. So buying other prospects like for example Dahoud is worthless, because he is not any better then Andre or Denis.
What we should do is to change the system. As we saw in some last matches Denis has got connection with Messi and he is complement with messi, because he can also play RW everytime Messi decides to move in the center. On the other side we should try with Andre- he still has lot thing to improve, but he has all needed skills to be some kind of mixture LCM and box to box player. I also believe he has good connection with Neymar, what is really important.
So IMO, we should play the toughest matches with Iniesta, but slowly trying to integrate new system with Denis and Andre in other matches. If it doesnt work, than we should spent some big money for CM in summmer 2018.
Also what Im thinking lately- We bought Arda for about 40mil and Paco for 30. With this 70mil we could get Reus, who can any of position upfront and also CM in some matches against weaker opponents.