Last Minute deal on Air North (4N): CAD 149 each way (USD ~115):
Whitehorse YXY to Vancouver YVR August 3rd
Vancouver YVR to Whitehorse YXY August 5th or 6th
There are 2 flights on each of these days for that price. You can book this on flyairnorth.com as oneway or as return. The price *includes* checked luggage of up to 40 kg (2 pieces) and on-board food (sandwich, warm cookie, beverages - beer costs extra AFAIK, cash only). Like the good old times!
Book until August 2nd, 23:59h Pacific Time. There is no mileage earning with Air North.
Of course you can stay longer, but the flights on other days than those listed above will cost more.