Sumlit
San Claudio Bravo
I dont really think the reason we refuse to buy great young players, except Neymar and Ter Stegen, is because we rely on La Masia. Our La Masia players have received very little trust over the years, and we have to go back 6 years since Busquets established himself as the last La Masia player. A guy like Samper isnt given any playing time for the first team.
I think the way Imbula has played this season, dominating one of the best teams in the league and doing great in the CL too is establishing yourself as a top player of that league. Marqinhos had established himself in Serie A as a great young player IMO when PSG bought him after his great season there. We cant just wait for years to let other clubs buy great young players and only try to show interest once they join big clubs. If you think guys like Griezmann, and Mangala were established world class talents in Sociedad and Porto, then so are guys like Imbula and Veltman in Marseille and Ajax. I dont think a guy like Danilo is better than Fabinho. Fabinho can probably be had for 12-15m. I dont think we will buy any of these guys though and they will probably go to some rich club in England.
I think the best idea is to gradually ease great young players into the team and not simply buy players because we have failed to plan for the decline of guys like Xavi and Iniesta. I agree that Koke might be a good purchase. Buying both Koke and Imbula is reasonable. At least its a better option than trying to go after Verratti or signing some aging Arsenal player like Cazorla or medicore guy like Pjanic with no potential to reach world class level.
Barca haven't needed to invest heavily in projects from outside because they've had a steady quality supply of them from La Masia. It is only recently that has begun to not pan out for them, or more accurately, failed to reach the levels it had in previous years. After Thiago, none of La Masia projects have managed to ascend from project player to staple player. It might be that now they will need to look outside from some project players to supplement their ranks.
Marquinhos wasn't an established player when PSG bought him, Bertus will tell you the same in all likelyhood. He was a very promising young player, but not established yet. He established himself at PSG, and quite possibly this season.
Once again, I told you I only included Mangala for his price, he was bought as a project and still is. Griezmann is a world class player and was a world class player before Atletico bought him. There's no comparison.
As to your last sentence, to ease young players into the team you need great players to take main minutes and allow for the easing of the young ones. Barca need starting caliber players at midfield right now and cannot really afford to gamble on projects.
I'm not opposed to buying the young player, but only if he comes after an already world class midfielder. There's no escaping the fact Barca will need to go get a midfielder from a top team next available window, and that they will have to spend significantly for him.