Purchase orders

SOLVED

On occasion I need to enter POs with a lot price.  So many items on the PO, all with valid part numbers and various quantities, BUT with a zero dollar amount for each, with a final "lot" part number for the total amount of the purchase.  Once the PO is received the current cost of each item is now Zero dollars.  Not ideal.  Is there a better way to do this that does not change the current cost?