Sunwing is a charter. They fly to Roatan (non stop I might add) only in high season.
Sunwing flew to BZE for 3 years (I went with them each year they did so) and offered packages in Belize City, San Pedro, San Ignacio and Placencia. For the broken out flight to Belize, I paid anywhere from $425CA to $575CA.
Last year Sunwing stopped going to Belize. I flew USAirways and paid $750CA...and that's only because I had the patience to wait until 3 weeks out for the prices to come down from almost $900 on all the American carriers out of Toronto. Of course, if one is staying in San Pedro, one must add in the cost of getting to and from the island itself.
Sunwing, which is one of Canada's premier charter airlines, continues to offer flights to Mexico, Cuba, Dominican Republic, Honduras, Costa Rica, Panama and Venezuela. Why not Belize?