I agree that the flop bet was too low. I put opponent on a straight draw only and not a better hand than me. Opp played this hand so weak that after I got my boat all I thought I could do was put small bets on the turn and river that he couldn't resist.

With this read, if I already have a boat on the turn then the maximum bet that opp is willing to call to draw to a straight is the best bet, provided that he doesn't already have a better hand than me, or can't draw to one.

I've been known to be wrong on my reads.