Car insurance car value

[Demented]

Afternoon all,
I'm currently looking for insurance for my first car, and having a play about with different prices for the estimated car value I've found putting the value to £12.5k is £400-£600 cheaper than using its real value of £3.5k. So I'm wondering if anyone can tell me why is that? The info I've found online says it shouldn't really affect the premium, but it obviously does in my case.

[Lozw86]

You are more likely to take care of and avoid an accident in a more expensive car? An old banger worth a few hundred quid however..

It's all based on statistics and likelihood of a claim

[Demented]

Makes sense I guess, well as much as insurance can anyway lol.