php – get_results() doesn’t fetch the result

I am trying to fetch offer_price from my db table but it is not showing any error just shows blank screen.

if($make=="1" && $model=="MDX" && $year>="2001" && $year<="2004"){

        global $wpdb;

        $results = $wpdb->get_results("SELECT `offer_price` FROM wp_cost_estimation WHERE make='Acura' AND model_name='MDX' AND year_from>='2001' AND year_to<='2004'");

        foreach ($results as $result) {
              echo $result->offer_price;
          }  


}
else{
    echo "try something else";
}

my desire result is offer_price= 300