OMG, I just got my car a few days ago, and this evening I was at a gas station changing the passenger side front tire.. It got slashed on the side.

I have a feeling I caused it. I was driving out of a friend's house and felt it pull to one side and the low tire warning was on. So I drove to the gas station... when I went to put air in, I felt the air coming out the side, so it might have been a small leak on the "surface" side of the tire, but from driving with it flat,(didn't feel flat), I might have sliced it with the rim

Stock rims / tires I read on the tire Michelin Pilot Sport 235 40 ZR 18, but on tire rack it doesn't show that size as the stock size.. wtf?

I priced the same stock tire and it was $269!!!!!!! I can't just put a different brand on there, it will look dorkish and ride like a pos.. arghhhh....

Any ideas if to change brands? Cheaper? Stick with the Michelin?