Durga,
Komk-erdat is the document's creation date and filled internally by SAP. For sales orders this is order creation date in SAP and for billing documents it is billing document creation date in SAP.
Komk-audat is the document date. You can manually input a date for this field in sales orders (The purpose? To track the sales order date in case of late entries to SAP by salespersons).
Komk-prsdt is the pricing date. The meaning of this field speaks for itself. Pricing records are read specifically for this date.
Komk-fbuda is PGI date if it's not a service sale. In service sales, this field equals to sales order date.
what does your vtfl settings look like for pricing? Can you share screenshots for relevant item categories?