The perfect time to buy bitcoin was  when it started its journey, as for now,no can say what are you going to deal with in future,maybe if prices drops in october due to fork,will be right time to buy,but what if it does not effect btc that much and its price continue its rising journey then its also not gonna be perfect time..so there are very few perfect moments in market when actually what you do is perfect, so if feel like you wanna buy and you can just go for it,its always a risk game and is always going to be.