Walsh likes this. He tried this with Sigurdsson, Walcott, Tosun, Bolasie etc. So we have tried what you want the club to do. I'm not exactly happy about the results. Of course you will say we should buy better but Walsh and Koeman didn't buy shite on purpose.
I'm in the opinion we should be clever in the market. That means maximising the value of the money spent. There are several clubs that are pulling above their weight in major European leagues by doing just this.
Note that transfer fees are not the only thing that matters, wages need to be considered as well. Younger players tend to have smaller wages so we can have more of quality players that way.