^ that's what i did...bought a used set that way and used the tires for 2 more seasons before selling them. there's always people looking to put tires on with just a bit more tread to pass safety when they do a lease return.
and yes go for smaller size tire for winters. the door jamb and manual will show the proper M+S sized tire.
and as others have stated avoid the dealer purchase. really you don't need star rated tires.