When you add items to your stock reception, you can always go back in the system and see what items you added, how many you have added and at what cost you bought the items, if you have previously stated it.
How to see previous stock receptions:
Click on Inventory
Then you click on Stock in the top right corner
Click on Completed stock transactions
Here you can see all your previous stock receptions and transfers.
Click on any inventory transaction for further information.
If you wish to see either Transfers or Receptions, just press View and choose one.