Oh behave. You think most fans would be happy if we only bought "unpolished gems" like Sturridge, Gomez and Coutinho, and carried on selling our best players like Suarez, Sterling, Mascherano and Torres to bigger, richer clubs? Within days there'd be a shitstorm about "lack of ambition" and "lowered expectations from a selling club".
Nobody would be stroking their chin and saying "yes, how wise, this is smart moneyball business at work! Hooray!" Not least because there's no such thing as a smart money ball business that works in this country.
Not to mention that most of the "unpolished gems" we sign are actually "unflushable turds". You listed Sturridge, Coutinho and Gomez. Why haven't you listed Borini, Adam, Allen, Assaidi, Alberto, Aspas, Mignolet, Illori?
We are a big, rich club. We should be trying to buy top players, like we did with Sanchez and Costa. Just because we waste big money on mediocre players like Lallana, Sakho, Balotelli, Markovic, Carroll, Benteke etc, doesn't mean that we should suddenly decide that we only buy young players for 5-15m - with an obvious view to selling them at a profit. We waste just as much money in that bracket.
We need a mixture of proven quality, usually at high expense, and younger players. And we need those players to be of a higher quality. That's a scouting issue, certainly. But the one crucial factor in consistent success in this league is spending lots of money on players and wages. Moneyball is a fantasy.