Purchasing Info record will be having the updated price.
How is the price in info record update, ie if i have not created the po for a month or so, but the price will be as last month but what is the case of material such as oil / fuel which may change hourly. how is that price updated in the infor record.
Price in Info record is not updated only via PO, it is updated via Quotation, Contracts, Scheduling Agreements also.
Go to ME11, here in Purchasing org data 1 screen, click Environment > Order Price History and Quotation price history
OR check transactions ME1E - Quotation Price History and ME1P - Po Price History