Hello Top Eleven players! to sell or not to sell?

[Pacurar]

Hello there managers! i'm new in this game, lvl 1, and i dont really understand the auction market, to be more exact what players should i buy and what players should i stick with so I can have good players on next level . I have a player (see attachment) and don't know for sure if I should sell him or keep him for lvl 2 because he is young, good selling price but low on stars. Thanks in advance!