Hi,
One solution could be to create a custom field on the table product and with the label "displayprice" in HikaShop > Display > Custom fields, then edit the view "product / listing_img_title" in HikaShop > Display > Views.
In this view replace the code:
	if($this->params->get('show_price','-1')=='-1'){
		$config =& hikashop_config();
		$this->params->set('show_price',$config->get('show_price'));
	}
	if($this->params->get('show_price')){
		$this->setLayout('listing_price');
		echo $this->loadTemplate();
	}
By:
if(isset($this->row->displayprice) && $this->row->displayprice == 'no'){
	if($this->params->get('show_price','-1')=='-1'){
		$config =& hikashop_config();
		$this->params->set('show_price',$config->get('show_price'));
	}
	if($this->params->get('show_price')){
		$this->setLayout('listing_price');
		echo $this->loadTemplate();
	}
}
Then in the product edition page, just set "no" in the custom field for the products with variants.