I have a 2007 IS350 and am in Minnesota which has gotten about a foot of snow in the last couple of weeks and with the summer tires the car was completely unable to move, without checking i had thought it was using all season tires. I got a similar quote from the Lexus dealer, tires and wheels for 2300. I went with the Michelin Pilot Alpins, as i had them on my last car (01 Audi S4). It certainly made the car better, but seriously, two inches of snow can still literally disable the car. Any ice at all under the snow, which is hardly uncommon here and the traction light comes on and the car simply won't move forward. And the Etc/Power/Snow switch which i believe electronically just starts the car in 2nd gear, makes it worse not better, it can take 30 seconds in "snow mode" before the car gets moving. It's really maddening because like others who've commented on this thread i've really loved everything about the car right up until the snow fell. i knew a RWD car would be more difficult in the winter (for several years i drove a V8 Mustang, RWD) but i never dreamed it would be this bad. Given the climate in Minneapolis i think i am going to sell the Lexus next summer and go back to Audi with maybe the S5.
Just my .02