[jalapenos]

It's an old solution to value-based taxation that's very simple and effective:

If someone declares a value, the other party can take advantage of it if it's off the mark.

So if the value is self-assessed, the state has the option to buy at that price (and vice versa if state-assessed).

This nullifies cheating without any complexity or contention required.

You won't undervalue your property to get an e.g. 30% lower yearly tax rate if that risks the other party then buying it to realize a 30% profit (and 30% of total loss for you).