I just renewed my insurance with the same broker who sent me three quotes from different underwriters. I paid £2400 last year.
One quote was for just short of £5000 which went immediately in the bin. The quote from the previous underwriter was just short of £3000 with the same terms as before and the one I went for was £3300 but that included an extra £1m third party liability cover (to £3m) and a different type of excess. Whereas before I had a £750 excess on claims arising while under rental and £500 if I was flying, I now have a limit of £750 below which I cannot claim but no excess for any claim above that. So.... if I do £1000 of damage I get £1000 back. That struck me as being a good idea. I also seem to have got my AVN(whatever number it is) clause back giving me cover against war risk etc which was removed last year. Nevertheless, I have had an increase from £2500 to £3300 as well which is a fair old jump!
Quite where the guys with the £5000 quote were coming from I don't know!