Traveling from Montreal to Hong Kong in August. Best to buy airfare now or wait?

I don't like sites like expedia, etc. I will book directly with Air Canada, but I've been checking prices recently, and they seem to be going down. Right now I'm looking at around $2000 with all taxes, which is a lot of money. Do you think it will be cheaper if I wait till June or July? If I end up paying like $100 more at the end it's no big deal, but if I book now, then see a $500 drop, I'll be pissed off.