Role Based Pricing - Manual Order

woocommerce_extension.php

function woocommerce_ajax_add_order_item_meta( $item_id, $raw_item, $order ) {
  	$product = $raw_item->get_product();
  
 	$rolePrices = $product->get_meta('_role_based_price' );
	if (!$rolePrices) return;
	$userRole = array_shift($order->get_user()->roles);
 	if (!isset($rolePrices[$userRole])) return;
  
	$grossPrice = $product->get_price_including_tax();
	$netPrice = $product->get_price_excluding_tax();
	$taxRate = $grossPrice / $netPrice;
  	if ($taxRate < 1) $taxRate = 1;
  
  	$regularPrice = wc_format_decimal($rolePrices[$userRole]['regular_price']);
  
	$price = $regularPrice / $taxRate;
  
  	$item = $order->get_item($item_id, false);
  	$item->set_subtotal($price);
	$item->set_total($price * $item->get_quantity());
  	$item->save();
}

add_action( 'woocommerce_ajax_add_order_item_meta', 'woocommerce_ajax_add_order_item_meta', 99, 3 );