Aw, i didnt know this
always thought more expensive would last longer
All the players can last till they 'll retire
but younger scout list players are more expensive.
Those players, if they are 22 y.o., after two seasons in your team, they 'll gonna be 24 .y.o. 5* players. Then, they can do a +60% gaining in training (3bars, practice) or games. That way, at the end of the season, they 'll reach again the 6*.
So they can last longer as higher quality players than the older ones.