Winter tires (snow tires) are something that is "free of charge" for anyone who plans to keep their car for more than 50,000 miles.
My rationale goes like this: The original set of tires that came on the car is not going to last longer than 40,000 miles. That means that somewhere around the 40,000 mile mark, you are going to have to buy a new set of tires. Rather than doing that, if you buy a set of snow tires when you first get the car, you will get 80,000 miles out of the two sets assuming equal use of both, which is a reasonable assumption for most of Canada. Your total tire expense over the 80,000 mile lifetime of the car is the same, but you get the benefit of having snow tires for the winter season.
The only additional cost is the price of the extra set of rims. It takes me a little over half an hour to change the 4 wheels in my driveway each spring and fall.
Michael
PS: In the Province of Ontario, you will get a discount of a minimum of 5% on your annual insurance premium if you use winter tires. Over the course of 5 or 6 years, that's enough to pay for the rims.
PPS: The only thing I don't like about snow tires is that they often are noisier than summer tires. Last year, I bought a new set of 'Conti Winter Contact' snow tires, and found that they are very quiet, no more noise than the summer tires.