Change Item Price when Creating Purchase Order via PHP in Netsuite - netsuite

Question

I am attempting to create open purchase orders in Netsuite during a system migration using Netsuite's PHP Toolkit for 2019_2. I am able to create the purchase order and line items without a problem, but I cannot figure out how to change the item cost on the line item. Setting the line item extended total works, but setting the rate field does not. Can anyone shed any light on why the price is not being set?
I've tried both $poi->item->rate = "5.00"; and $poi->item->rate = 5.00; with no success. The documentation says that this field is a string.
https://www.netsuite.com/help/helpcenter/en_US/srbrowser/Browser2019_2/schema/other/purchaseorderitem.html
$service = new NetSuiteService();
$po = new PurchaseOrder();
$po->tranId = 'PO111111';
$po->tranDate = '2019-03-27T00:00:00';
$po->approvalStatus = new RecordRef();
$po->approvalStatus->internalId = 2;
$po->entity = new RecordRef();
$po->entity->externalId = 'VENDORNAME';
// Create PO Item
$poi = new PurchaseOrderItem();
$poi->item = new RecordRef();
$poi->item->externalId = 'ITEMNUMBER';
$poi->item->rate = "5.00";
$poi->quantity = 10;
$po->itemList = new PurchaseOrderItemList();
$po->itemList->item = array($poi);
$request = new AddRequest();
$request->record = $po;
$addResponse = $service->add($request);
if (!$addResponse->writeResponse->status->isSuccess) {
echo "ADD ERROR";
print_r($addResponse);
} else {
echo "ADD SUCCESS, id " . $addResponse->writeResponse->baseRef->internalId;
}

Answer 1

Set the rate on the purchase order line instead of trying to do it on the item record.
$poi->rate = "5.00";