Young people are impatient and want a 'drifty' car as soon as they pass their test, my self included when i was 20. However it simply didnt happen for me as im sure for many others, I had to drive a shitty civic for a year to get 1yr ncb which cost me 1800 for the first year (tpft) and then payed 1600 (tpft) odd for an s13 at 22 or what ever it was, some insurance companies even quoted me higher premiums because i wasn't born in the uk even though i've lived here since i was 5, so i didnt see how that would make any difference to my driving ability as i'd never driven abroad and took the same test as everyone ells.
Anyway I still pay 900 odd fully comp at 26 for a slightly modified s14. As others said insurance quotes don't make a whole lot of sense and they are massively discriminating on age/sex/job/location the lot, Either pay up, be in the insurance goldy zone (30 years old in the countryside with a garage, none modified car, nothing to hit for miles etc etc) or be patient, buy a shitty car and don't crash for a year.