Different levels have different prices. They dont have structured timed 'sessions' like trackdays.

That one is the 4 hour one, the gold is the 7 hour one etc etc

The 'thrill' at £99 seems half decent value.
http://www.treatme.net/experiences.php?experienceID=143

Si's back again in pic 3 this time He says the time given in the car is depending on experience. If your good you obviously get more than if you have to be trained etc...