Interesting comparisons to your insurance rates. While I am located in Canada (Ontario) insurance rates vary depending on coverage also. Do you have Public Liability only (our PLPD and your TPFT), or include Collision (your Comprehensive)? Collision/Comprehensive always adds a varying cost increase to your coverage. In Canada, the term "Comprehensive" covers things like your windshield/windscreen for damage due to pitting or cracks.
My health details (I am Type 2) do not affect my insurance rate unless my doctor declares that I am a high risk with any medical condition then it becomes a matter of determining the insurance risk that the insurer must take (same as being licensed to drive).
My 2 vehicle, 2 drivers (myself and spouse, both over 65) - Dodge Grand Caravan and Ford Sport Trac - insurance here in Ontario Canada is $2023/yr (CDN dollars or about £1149/yr or monthly $169/£96). We are many years driving, accident-free and no traffic offenses - so the best available rates for us. Ontario has the highest rates in Canada. Another consideration for insurance coverage and cost is the age of the vehicle. For example, my Ford Sport Trac cannot have Collision/Comprehensive because of its age (2005) but is covered for PLPD/TPFT. The Dodge Grand Caravan is only 2 yrs old and is fully covered.
There are too many variables to consider for insurance coverage so asking someone else about how much they pay can only be used as general sense of the different insurance companies. Shop around, get quotes, and be honest and upfront about yourself and your vehicle(s). Leaving out a detail or 2 because you know it will increase your rate and you want a lower rate can come back to haunt you if you ever need to submit a claim - you could be denied compensation. While discrimination is not allowed, a "sin of omission" on your part could bite you in the rear later on.
Shopping for a better rate saved us close to $1000/yr (about £560) and we switched to one of the largest insurers. The new rate is the $2023/yr CDN (or £1149/yr).
LOL, to pay only £250 per year (about $440 CDN) would be a dream come true