I'm trying my best to forget about stars, as others have said they mean jack **** on the pitch.
I'm in the same boat two thirds of my squad are 4* but range from 26-29 in quality I'd say maybe 75% will be close to 30 by the season end.
Looking at my friends level four league most will be good enough to compete, I think.
I sold my lowest ranked striker three days into the season for what should have been something better, didn't work out, I believe this game favours underdogs, how many times does a a defender of poorer quality rob your striker of the ball.
I bought no players at all in between the close and start of the league this season, bided my time, OK, it may have took 5-8 days to get what I wanted but 4 18yo and 1 19yo for 7 tokens was a a bargain, big fees but you expect that with youngsters of good quality.
There are definitely bargins both before and after the mad rush.
Guess you play it the way you feel is best for you.
Just watched a 18yo 4* 29, go for 1 token, only needed 5 skill points for 30, I fancied him myself but I know the bidder watched him many times this season, one look at his stadium, strip and emblem tells you not to do battle.