"Barca will never do ...." is something I heard many times, and yet they ended up doing it.
They blamed Real for buying expensive mercenaries, just so they'd buy Zlatan for 69m eur the next week.
I heard Ian here saying how he'll never understand how could Juve pay so much money for Thuram, a RB. How much did Barca pay for Dani Alves?
Barca did a fantastic job with the youth school. They produced many players so they didn't need to splash money for those positions. What would have happened if they didn't produce these players? We can't know, but we can assume what would they have done, judging by what they did for those positions in the team, for which they don't have a quality youth product. The striker position for example. 69m for Zlatan and now 40m for Villa. Eto'o and Henry before that. The RB position. Hell, even for the CB position where they have youth products, they paid 25m for Chigrinsky.
Barca won't keep producing these youngsters forever. Look at Ajax now. How many youth products made it to the first team in the last 5 years and how many of them are world class? If the same happens to Barca and they don't produce top quality for some 4-5 generations, how much do you think they will spend on new players?