Thank you all for the advice!!
I sold my lvl 4 trainer (14k/wk) for a lvl 2 trainer (~4k/wk). I think y'all are right - that this extra 10k will add up and be worth it! I'm not very serious about training... just getting a well-rounded team. So this season I got beat by the winning team (I mean they won the div.) in the first round of playoffs... but I set effort lower than theirs to see if I could make a run (big mistake.. urgh).
So I will focus on what you all suggested (salary efficient, defense-based team, game shape, well-rounded team).
Thanks!