My family keeps the tires on separate rims so the tire beads don't wear out from mounting/dismounting.
If you look around on the internet like on Craigslist, you can find a good deal on winter tire/wheel package.
My rims and tires were on a local Craigslist for $1000 from a wholesale car dealer. Driven only for 100 miles and were pretty much brand new.
2008 BMW Individual E66 750Li (Azurite Black Metallic/Rust Brown Merino Leather)
BMW Individual Composition Package
Luxury Seating Package
Adaptive Ride Package
Active Cruise Control
Rear Ventilated Comfort Seats
Rear Entertainment Package
2006 Mercedes-Benz S500 W220 (Flint Grey/Charcoal Nappa Leather)
Electronic Trunk Closer