So you know, no one here works at the Hamilton Box Office (if they do, they have kept quiet about it), so there's no way any of us could say with certainty that on a random day in August you'll be able to get tix for March, 2018.
Some of us have had success going to the box office and asking about future availability and some have not. You need to be prepared to get limited view seats there.
It also will matter if they put more tickets on sale between now and your visit as they are only selling now thru March 4, 2018.
So if they extend sales by your visit and you get lucky at the box office and you're willing to take partial view then yes, you might get seats at regular price (with no fees!).
Only you can define "good seats" and "decent seats"