I quite agree that you proposal makes as much sense as selling fire insurance where
- Tier 1 would be the most expensive, covering the full costs of any fire damage suffered;
- Tier 2 would pay 75% of the costs of any fire damage suffered;
- Tier 3 would pay 50% of the costs of any fire damage suffered; and
- Tier 4 would pay 25% of the costs of any fire damage suffered.
I mean, after all, EVERY house has a "preexisting condition" that means that it MIGHT catch fire and burn down.
Of course, the rate structure would have to be rather complex since it wouldn't be fair to expect someone whose house is only worth $100,000 to pay premiums based on the fact that the "average potential risk" to the insurance company is $200,000 - would it?
No, each policy would have to be based on an annual assessment of the actual replacement value of each individual house so that those people whose houses are worth less than the "average potential risk" would not be subsidizing the insurance of those people whose houses were worth more than the "average potential risk". And, of course, any benefits paid would not take into account any changes in the actual replacement value of the houses since the last annual assessment (unless, of course, the actual replacement value of the houses had declined).
And, of course, your proposal makes as much sense as adjusting the municipal taxes for (let's say) "policing" to reflect the crime rate in individual areas.