$411 from Halifax ($408 from Toronto) to Guayana, return, in December (all taxes included) (on the Google site, click on the calender button for the cool graphic). No visa required.
Getting there from Halifax for $411 is a 23 hour journey, but only 13 on the way back. Delta does fly to JFK New York from Halifax, but for $411, they insist you transit via Toronto to JFK, using Westjet.
But South America for $411 !
A $45 visa is required to visit adjacent Suriname. It is $125 for Brazil. You will need a Yellow Fever certification to cross a border in that region. There are no direct roads to Venezuela. Guyana has a high crime rate, directed at tourists!
The airport departure tax is G$4000! Although, thankfully, that is only about 20 bucks, Canadian.
Guyana is always sunny and warm (and humid), but December is the beginning of the rainy season (heavy afternoon rain showers). There have never been any hurricanes hitting Guyana.
If you do it right, you could visit 4 countries (5 if you go to Venezuela via Brazil) with 4 different languages (English, Dutch, French, Portuguese) and 4 different currencies. More impressive, every border is a ferry crossing!