We must face a very simple reality. There are now 4 teams in the Premiership that have greater revenues than us. That means they can spend more on their team and breakeven. As we have to spend less but beat them if we want to be in the CL let alone win the Premiership we have to be smarter than them.
Now in reality that is not always as difficult as you might think.
For instance if we sell Torres to Chelsea for 50m quid they will take 50m of their revenues and hand them to us. We will then have more revenues than Chelsea so we will be able to spend more on our team than his. He will have Torres but the 50m he invested in his transfer fee will erode to zero over the next 5 years by which time Torres will be 32. And Chelsea still need to pay him 180k a week to perform on the pitch which may or may not bring them value. We could afford to pay a player 180k a week better than them as we have more revenues and we have additional revenues to spend even further on our squad.
As you rightly point out what we should be doing is buying an Alexis Sanchez or some similar player at say 23 so that we can afford to sell our best players near their peak and get the best players into replace them. It maybe better to sell say Suarez at 28 for 40m so we can get a 40m young superstar into replace him rather than wait until he is in decline at 29/30 and only get 15m which will not buy us the best replacement.
I agree with most of that, but bear in mind Torres wanted to leave and had he stayed it would not have prevented us signing Suarez. We do not know what may have happened with Carroll - it could be we may have tried to buy him anyway, albeit for less, or that he may have become a summer target instead.
Another point is that we're clearly going after players for whom there is not a mad scramble for. Someone mentioned early that Downing (in essence) was not a good signing as none of the other 'big' clubs were in for him. As you rightly say, competing against clubs with superior revenue, plus European competition to offer, is always going to be difficult. We looked at Young and we bid for Jones but ultimately lost them both to the Scum. But I'm sure we can all agree that spending wisely trumps spending big every time.
Where I was trying to highlight those taking moneyball literally is that there seems to be a belief now that we will sell players regardless of their contribution, just because they meet the criteria to be sold. What I would say is that it would be idiocy to sell a key player on that criteria alone, ie at his peak and being offered maximum money.
Where moneyball does
make sense is that, once we have a successful team that we know
will win trophies because it is greater than the sum of its parts, then selling a player at his peak knowing we will have a quality replacement lined up is sensible because it wont damage our competitiveness. We survived selling Rush and we survived selling Aldridge as examples.
The key, as ever, is for us to actually start bagging some silverware. Once we are seen
to be able to match rivals who are spending more than us and who are padding their squads with superstars who can't even make the bench, then
we will come back into our own as a club and as a preferred destination for players.