Enter and update item cost for all organization

Hi,
We have 3 operating Units, which has the same item cost.
 
Currently we are not able to user one costing organization as a Cost Master (Parent - Child) relation as WIP is installed.

So Could some one please let me know whats the way to achieve or update all the item cost at one go across operating unit.

Also let me know is there any standard API available to load and update the cost of items periodically