This is the world's expensive airport -- http://www.cbc.ca/money/story/2005/11/15/gtaa-051115.html
If you're a private pilot, you can get dinged with a landing fee close to CA $200 even in a light plane, and that's before ramp fees, parking, etc. If you're an airline passenger, your share of the obscene landing fee (over $13,000 to land a 747, vs around $3,000 at other Canadian airports) is tacked onto your ticket price.
The high fees have nothing to do with the fact that the airport's busy -- it has about the same traffic as Philadelphia Intl (PHL), which had no landing fee for light aircraft when I visited in 2003 and charges around US $2,000 for a 747 to land. Something's just broken somewhere, and nobody will take responsibility for the problem.
If you're coming to Toronto, use CYTZ (downtown), CYKZ (northeast), CYOO (east), CNC3 (northwest), or CZBA (west). CYTZ has a landing fee of around $10 for a light plane (watch the ramp fees at Porter, though!), and the others have no landing fee at all.
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