Insurance companies seem to pull these numbers out of their asses.... That or they pull a giant lever, and numbers spin and whatever they settle on, that's what they tell ya

I've gotten everything from "we don't insure this car" to random 4 digit quotes, was with Liberty last year which was 650 or there abouts and come renewal time they wanted 1200, talked them down to 850 but they couldn't go lower, so I took my business elsewhere. Axa gave me by far the best quote at 545 for the year so that's what I went for. Shopping around is absolutely essential!