The price in a contract item is not changed when changing a condition valid for a future period (only the field EKPO-PRDAT gets set to the end of the current period if the conditions are maintained from with in ME32K). Also even when the time has come, so that the changed validity period becomes the current one, the entry in the database does not get updated.
The database entry for the contract item will only be updated by running RM06ENP0 or manually editing the contract with ME32K - and this will not create a change document - this is because system is only concerned with the current validity period when it comes to changes' in the document.
Also when displaying the contract (ME33K) it is checked whether EKPO-PRDAT lies in the past. If this is the case a pricing is performed to calculate the current price and display it (only display, no change on the database).
Related notes / content:
685117 Net Price in Info Record or Contract is wrong