Let me clarify:
If you bought a new property, you will declare it at the price you bought it, but price should be above or equal to FBR valuations. Once you have declared it, you will repeat same value on future wealth statements until its sold.
Also I would like to mention here, If the property was bought before last tax year but was not declared, then it becomes a lot more complicated as it becomes a hidden asset. You have to declare it on tax year it was acquired on. If you look at last two amnesty schemes, government asked to declare property at current valuations even if you bought it for 1000 rs 30 years ago. This is the main reason people don't become filer, as they will end up paying penalities for hidden assets.