Any Canadians (or people who are familiar with buying plane tickets in Canada) have advice for me on how and where to buy flights to Cuba?  I’m especially interested in something in or around Vancouver, BC.
As always, any positive help is appreciated.  The sooner the better!!!!!!

i’ve usually flown with sunwing, http://www.flysunwing.com
air canada, http://www.aircanada.com also flies to havana regularly.

So my dilemma is that I’m trying to buy tix in Vancouver, but all I need is to get a flight from Cancun to Havana and back.  Sounds weird, but believe me it’s what I gotta do.  I’m trying to decide in between going to a travel agency (and possibly paying more) and just going to the nearby airport. 
A strange dilemma but I already got some cheap tix and now just need to get to la isla from Cancun.