We went on Tuesday and had a really good day, weather wise the best day of the week. (Despite being cold by celtic complexion still managed to get sun reddened!)
It was costly though; we paid on the day because the weather forecasts were so ropey and it cost us £20 more than if we'd booked 12 hours in advance over t'internet.
Prices at this time of the year £20 per adult, £18 per child over 2 years. T'internet price (at least 12 hours before opening, they are going to be strict about this) £15 per adult, £13 per child.
I did try to get an answer about whether the £5 discount would apply to all the prices in high season or whether there would be more of a discount. One person says yes but checked with her colleague who said that you won't know the prices until you go onto the internet.
I didn't manage any of the real white knuckle rides, but my 7 year old was brave enough to accompany on the big dipper and Grand National...Quite apt after my 50p e/w on the winner last week.