We can't buy established superstars for huge money as a way to get us out of this mess. There is simply too much work to be done on the squad. It needs to be a combination of getting the right up-and-coming players from lesser leagues (primarily Bundesliga, Ligue 1 and Serie A), as well as quality players from midtable Premier League clubs that are ready to step up and can be had for reasonable money.
Look at how Liverpool and Arsenal got to where they are. In the first transfer category (finding quality in lesser leagues) we have players like Firmino, Fabinho, Salah, Allison, Konate, Gabriel, Saliba, etc. and in the PL proven category there is VVD, Rice, Mac Allister, Mané, Trossard, Robertson, etc. Now of course some of these were brought in for huge fees, but when that is the case, they had the right age and fixed a clear problem in the team (VVD, Allison and Rice being the best examples). You don't see Arsenal or Liverpool spending big on players like Varane and Casemiro, because they know it's not sustainable.