switch ($modx->event->name) {

    case 'msOnAddToCart':
        $res = $modx->getObject('modResource', 1);
        $defaultOptPrice = (int)$res->getTVValue('opt_price__default');
        
        $crt = $cart->get();

        $currentGoods = $modx->getObject('modResource', (int)$crt[$key]['id']);
        $currentGoodsOptPrice = (int)$currentGoods->getTVValue('opt_price');
        if(((int)$crt[$key]['price'] * (int)$crt[$key]['count']) >= $defaultOptPrice){
            
            $crt[$key]['old_price'] =  $crt[$key]['price'];
            $crt[$key]['price'] = $currentGoodsOptPrice;
            $crt[$key]['discount_price'] = $currentGoodsOptPrice;
            
            
        }

        $cart->set($crt);
        break;
 
}

//...
if($tvo = $modx->getObject('modTemplateVarResource', array('tmplvarid' => 999999,'contentid' => $product->id))) {
    $currency_type = $tvo->get('value');
    $currency = $modx->getOption('currency_'.strtoupper($currency_type)); //Значение курса
}
//...

$modx->setPlaceholders(array(
   'rating_count' => $middle,
   'rating' => $result,
   'ratingCount' => "(".count($all).")"
));

return $middle;

будем благодарны вам за публикацию решения

<?php
$d1 = $id;