I bought a set of four 18" Blizzaks on wheels, everything complete, for just under $1500.00 delivered.
+1
Purchased the 18" Blizzaks (LM25 Run Flats) from tirerack.com and mounted them on 18" rims on all four. The summer wheel set went into storage. I'll know better when the snow flies how they turn out, however I'm optimistic that the Blizzaks won't let me down. The rims I picked up for cheap and the tires were delivered to my door (Canada) for just over $1,000.
BTW, as previously mentioned, snows should be put on all four....