Well, I think we get a bit more snow on the south side of the lake, but I am 100% for getting a dedicated snow and ice traction tire. I used the Blizzak ws-60 in my EVO, the LM-25 in my bmw, and now the WS80 on my Audi... The difference between the WS (winter traction) series and the LM series (winter performance) was night and day... as big of a difference as switching from all season to winters, and from summers to all-season. If you want to have the confidence to drive 40+ mph in blizzard-like conditions, or even just driving 55-70 on snow covered roads with 100% confidence and safety, go for an x-ice3 or equivilent tire. Jesus though 300 dollars difference in price? Most likely they are ripping you off on the x-ice 3s. On a "normal" sedan size, 16-17inch winter rims, they run about 120 dollars each.
If you lived in like... Rural Virginia, Urban New York/Boston or like St Louis or something... Performance Winter would be an excellent option.
If you're buying rims, you should downsize your rims for winter, especially if you have like 18s, and your brake calipers are small enough to fit 17s or even 16s. The price difference can be hundreds of dollars. Unfortunately... you should have bought your tires about 5 months ago... tire places tend to gouge their prices this time of year when people start panicking after they realize those bald ass tires on their beaters are completely unsafe and they've already almost killed themselves a few times. Unfortunately some people DO kill themselves and others before learning that the time to put on winters is THE FIRST SNOWFALL.
But even then, there shouldn't be a 300 dollar difference in price, 400 for the rims is a set price (you don't have to get rims necessarily, just use your current stock rims and you pay a little more to remount and balance your tires each year, but if for example, you aren't going to keep the car at least 3 years it would work out in your favor... and say, 550 for the 4 quality tires. If they're saving you 300 between the 2 sets, something is fishy. Example, in the OE size for my car, tires are about 50 dollars more PER TIRE, 225/40/18, $183 for the Michelin $150 for dunlop winter max, but going to a 16" rim, which I can easily do on my car, The Dunlops Winter maxx are $99 a piece.
I'm not sure WHICH Kumhos they were trying to sell you, because Kumho in the U.S. doesn't even offer a winter tire, only all-seasons.