I recently had mine replaced after such a thing - the nice chaps who came along reckoned on about a grand for mere mortals like you or me, the insurance company pays about 5-600 quid.
Not normally, but check your policy first! Usually you just have to pay an excess (often £50) but they will want to repair it, if possible. Your friendly windscreen fitter will probably (hopefully?) say that he can't repair it though..... Hopefully the stone chip is quite big
