Round product price to nearest whole number based on an array of product IDs.

wcpb_round_to_nearest_whole_number.php

<?php

add_filter( 'raw_woocommerce_price', 'wcpb_round_to_nearest_whole_number' );

function wcpb_round_to_nearest_whole_number( $price ){
     global $post;
     $post_ID = $post->ID;

     $page_id = array('123','345','398','80');
    
     if(in_array($post_ID, $page_id)) {
          return round( $price );
     } else { return $price; }
}