It won't matter getting examples chap, as insurance is all based upon your insurer, you, your past, and where you live... Someone else might pay an extra £50, whereas you may have to pay £500... Only way to check is to get on the blower and ask.
As far as I'm aware it will be based on the amount of BHP gained? That's what flux go off anyway. So if you gain a lot of ponies, then expect your premium to go up considerably if your young.