I invested very early to go to level 5 YA - all my current players are graduates of that.
Went slightly mad during the stupid goalkeeper days and bought Tibon and his enormous wages just to see if that was my missing link to win (it was!), but that meant my finances didn't work anymore and I had to downgrade the YA to level 3...
Just nearing the end of the level 5 YA graduates coming into the team (maybe 2 more seasons), so I now either need to upgrade again or start buying in key positions (maybe for 4 seasons time) - I've got the cash now, just can't decide what to do...