How to know i'm not being ripped off on winter tires?

I drive a Chevy Malibu 2011 and i'm not sure exactly what type of winter tires to buy (New/Used), Brand, who to buy it from, how much it costs, etc.
I've had my car for less than one year and only had to take it for oil changes and once had my mechanic check my brakes, car's in good shape according to my mechanic.
Should i go to the chevy dealership or dealership where I purchased my car or take it to my mechanic and get his advice?
Any advice would be much appreciated!