Same kind of thing happened to me whent he car was just 2 weeks old. Big rock on the A14 jumped up and hit the bonnet leading edge just in the centre of the stripe.
I just live with it, like Max says, I expect to get a few more and when they are bad enough I will ge the whole lot done.
£300 sounds about right. I know what you are saying Max, but I have seen plenty of £50 spray jobs and you do get what you pay for.
I know this doesn't help but just so you know you are not alone