public function getPrice()
    {
        if (\Yii::$app->user->isGuest) {
            $params = [
                'combination_id' => $this->id,
                'user_group_id' => UserGroup::USER_GROUP_ALL_USERS
            ];
        } else {
            $params = [
                'combination_id' => $this->id,
                'user_group_id' => \Yii::$app->user->identity->user_group_id
            ];
        }
        $combinationPrice = CombinationPrice::find()->where($params)->one();
        return $combinationPrice->price;
    }