For anybody who posts to the USA regularly in the GTA and didn't know (I didn't) there is a firm in Markham and Mississauga called ChitChats Express who make daily runs down to a US post office and send out your mail providing the value of the letter/package is under $200 as it doesn't have to go through US Customs.
I had to send 22 packages out to somebody in Utah a couple of weeks ago, with Canada Post that would have been $3.50 each. As they were all to the same person I could put them in 2 separate boxes and the total cost was $34

Just a shame I'd I wasted 22 envelopes packing and addressing each one