System notes show changes on purchase price after editing item record.

Viewing the System Notes tab of an Item record shows changes on Purchase Price even though the Purchase Price field was not edited.

This happens when the Item record has a Preferred Vendor with a currency different from the Base Currency. If the Preferred Vendor on the Item record is a foreign vendor, the Purchase Price field will show in the currency of the Preferred Vendor. When this Item record is edited, the Purchase Price value in base currency will also be updated based to reflect the changes in the exchange rate.