UPS /. FedEx fees are negotiable if you appoint them as your broker of record and have a regular flow of shipments.
Or use an independent broker (or clear your own as I did 2 or 3 times a week for 20 years).
For a broker at Pearson, they can pretty much all do what you need so just go here:
http://canada411.yellowpages.ca/search/si/1/customs+broker/Toronto+M%C3%A9tropolitain+ON
Pick a few and call them. You can check their websites to perhaps get a feel but I expect there is little concrete information posted.
Try one out, if you don't like the service then switch. Your basic customs entry is pretty simple stuff that any broker should be able to process quickly. You''ll probably get lower prices if you can pay upfront or immediately rather than them having to carry your taxes and/or duty for any length of item. It's very competitive business so everything is negotiable.
Your could start with Hartwick O'Shea Cartwright or Delmar, it's been a while since I was involved, I didn't see many of the names on that list that I remember.

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
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