Pricing Fields Sorting

One other way to do that without modifying plugin files would be to add the code below in your them functions.php (or by creating a new plugin and pasting the code there)

add_action( "init", "my_init", 100 );
function my_init() {
    remove_filter("adverts_form_load", "adext_payments_form_load");
    add_filter("adverts_form_load", "my_adext_payments_form_load");
}
function my_adext_payments_form_load( $form ) {
    
    if($form["name"] != 'advert' || is_admin() || adverts_request( "advert_id" ) ) {
        return $form;
    }
    
    // do not show payment options when editing Ad.
    $id = adverts_request( "advert_id" );
    $ad = get_post( $id );
    if( intval($id) && $ad && in_array($ad->post_status, array("publish", "expired", "pending" ) ) ) {
        return $form;
    }
    
    $form["field"][] = array(
        "name" => "_listing_information",
        "type" => "adverts_field_header",
        "order" => 1000,
        "label" => __( 'Listing Information', 'adverts' )
    );
    
    $opts = array();
    $pricings = new WP_Query( array(
        'post_type' => 'adverts-pricing',
        'post_status' => 'draft',
        'orderby' => 'ID',
        'order' => 'ASC',
        'posts_per_page'=>-1,
    ) );
    
    adverts_form_add_field("adverts_payments_field_payment", array(
        "renderer" => "adverts_payments_field_payment",
        "callback_save" => "adverts_save_single",
        "callback_bind" => "adverts_bind_single",
    ) );
    
    foreach($pricings->posts as $data) {
        
        if( get_post_meta( $data->ID, 'adverts_price', true ) ) {
            $adverts_price = adverts_price( get_post_meta( $data->ID, 'adverts_price', true ) );
        } else {
            $adverts_price = __("Free", "adverts");
        }
        
        $opts[] = array( "value"=>$data->ID, "text"=> $data->post_content );
    }

    wp_enqueue_style( 'adverts-payments-frontend' );
    
    $form["field"][] = array(
        "name" => "payments_listing_type",
        "type" => "adverts_payments_field_payment",
        "label" => __("Listing", "adverts"),
        "order" => 1001,
        "empty_option" => true,
        "options" => $opts,
        "value" => "",
        "validator" => array(
            array( "name" => "is_required" )
        )
    );
    
    add_filter("adverts_form_bind", "adext_payments_form_bind");
    
    return $form;
}