Calgary to Lima, Peru - $748 roundtrip after taxes
There are some flights to Lima that are about 25% cheaper than they ever normally get from Calgary.
They seem to be available sporadically throughout the first part of 2012. The latest ones in the year I can find are near the end of May. A 3 day flexible date search on Kayak is the best way to find them.
Here's May 20-30 for example, which involves the long weekend, so that's one less vacation day to use.
http://www.kayak.com/flights/#YYC-LI...05-30-flexible
The price verifies on both Orbitz and CheapTickets (which is owned by Orbitz). But if you try Orbitz, the first time you click through it may say 'unable to confirm your selection', and then you have to click on 'Select' again, and it will verify.