Product cost calculation process in Oracle Costing for standard , Average, Periodic average, FIFO ,

 Hi Folks,

1. While creating Purchase Order, supplier will decide the item cost, in this case how our item cost will be maintained (Distribution business)

2. While selling Product due to market fluctuations/ margin reasons we will increase item cost in costing in this case while buying the item cost is 100$ on 01-Nov-2012, but while selling the same item cost updated as 110  on 10-Nov-2012, so Customer requested sales order on 01-Nov-2012, where we ship confirmed on 10-Nov-2012. how system will pick item cost in this scenario.

Note:- Please exaplain above 2 queries with accounting entries from Inventory, Costing.