Insurance costs

[JMGS4]

Just read about a guy who pays £4K per annum? and wondered if GB is now also the insurance rip-off (it wasn't in the 70s). For my S4 with all its mods I pay £349 fully comp with £300 waiver for all countries in EU + Switzerland + GB, Eire, Faroes etc (100Kkms and no garage). (Not behind old iron curtain)
Calculating up to what a 100% would be thats not more than £780 pa
Mind you we do start on 250% here! So a kiddy with a hot hatch may pay £2K. But where does the £4K come from? My GT2 costs no more than £500 pa!!!!