NetMecca said:
Taxi is the simplest, and not particularly expensive considering you will have to contend with luggage especially.
I think expensive/cheap is relative and very individual. If a person has been working all their life to save up $8000 to come to Canada with a family, $50 might be a week's worth of work or even a month's time worth of saving, after living expenses.
If money is a concern - some suggestions:
If you have a smartphone - you can connect to free Wi-Fi network at Pearson Airport, and probably other airports too. With this you can get directions and timing on public buses through Google Maps for example.
You can make free phone calls - check out applications like Google Hangouts Dialer - free calls across US and Canada.
If you do want a taxi - it will be cheaper if you walk from Terminal 3 literally for 1 minute onto the street. Check out intersection of American Dr. at Airport Rd, it is outside airport terminal zone and should be around $15 less in fare - what the airport authority charges all taxis. Order an Uber from there and pay about half of the cost of a taxi within the terminal.