Basic 2/4 Flush hand

[El Diablo]

I sometimes get confused as to how much certain hands are worth in smaller games and how much value I can squeeze out. Here's an example.

6-handed 400NL. Stacks $713.

Dude opens UTG. I call next w/ QJs. Button calls too. Blinds fold.

Flop 2s 4c 3s

PFR leads $35. I call. Button folds.

Turn (2s 4c 3s) Ah

Check. I check.

River (2s 4c 3s Ah) 6s

Ding! About $120 in the middle. $664 left.

He bets $75.

I do what?