Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Fort McMurray to Karachi as you normally would.
Within the past month, 19 users have taken a look at flights from Fort Mcmurray to Karachi Quaid-E-Azam Intl.
This is defined as Fort Mcmurray Airport (YMM) and Karachi Quaid-E-Azam Intl Airport (KHI). Codes like Karachi Quaid-E-Azam Intl Airport are often used to just call airports uniquely.