Thats bang on. Not many Lambo owners will be parking them outside the house in street, nor in supermarket carparks etc and you dont tend to use them as day to day runners. Those that can afford one usually have owned/driven similar before and so statistically, insuring one Lambo is probably less of a risk than several CTR's around the country
Yup it's based on statistics and that can seem illogical.
If i garage my car or my motorbike then my insurance goes up. Makes no sense, until you consider that fact that my area is mainly flats. Therefore it only takes one claim out of the few that garage their cars and the price goes up.
In your case the 21 year olds who drive lambos (as there will be some) don't claim much, cause them no bother and thus aren't a risk.
My wife is 31, has been driving for 5 years and she puts the cost of my CTR up. Makes sense, she's younger than me and she's had less experience. Thing is she also reduces the cost of my VX220 policy. Why? I'm guessing it's cos there aren't many claims from 31 year old lassies on what is traditionally a blokes car.....therefore lower risk.
You notice this kinda stuff much more on the VX as a few big claims out of a small "population" of cars can suddenly rocket up the insurance, with some insurers (greenlight for one) basically saying they wont touch the car at all now.
EDIT : I've just remembered that the VX also costs £200 to insure....compared to £450 for the ctr. mental.