Why is this get_post_meta returning the wrong value?

Trying to show a display notice based on the previous page, using it's post ID.

The problem is that the post meta value is stored in Wordpress as 0 (zero), but my statement is returning it as being true, when it should be false.

$previous_page = url_to_postid(wp_get_referer());
$consultationFee = null;
if(get_post_meta($previous_page, '_wp_page_template', true) == 'template-procedure-minimal.php') {
    if(get_post_meta($previous_page, 'consultationFee', true) && get_post_meta($previous_page, 'consultationFee', true) === 0) {
        $consultationFee = false;
    } else {
        $consultationFee = true;
    }
}
var_dump($previous_page, get_post_meta($previous_page, 'consultationFee', true), $consultationFee);

C:\wamp64\www\bellavou\wp-content\themes\bellavou\template-request-consultation.php:11:int 3209
C:\wamp64\www\bellavou\wp-content\themes\bellavou\template-request-consultation.php:11:string '0' (length=1)
C:\wamp64\www\bellavou\wp-content\themes\bellavou\template-request-consultation.php:11:boolean true

I notice the var_dump of the value is being returned as a string. IS this right? This should be an integer. Anyway, even changing the IF statement to check against a string ie. === '0' returns the wrong value still.

What's happening?