If you want to hide the whole website’s product price and want to make it appear only for login users then this article is a catch for you.

1. Create file di.xml on app/code/Magemonkeys/Hideproductprice/etc

<?xml version="1.0" encoding="UTF-8"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="MagentoCatalogPricingRenderFinalPriceBox">
        <plugin name="price_hide" type="MagemonkeysHideproductpricePluginHidePriceBox" sortOrder="1" disabled="false"/>
    </type>    
</config>

2. Create file HidePriceBox.php on app/code/Magemonkeys/Hideproductprice/Plugin

<?php

namespace MagemonkeysHideproductpricePlugin;

class HidePriceBox
{
    protected $_customerSession;
    public function __construct(        
        MagentoCustomerModelSession $customerSession    
    ) {
        $this->_customerSession = $customerSession;        
    }
	
    function afterToHtml(MagentoCatalogPricingRenderFinalPriceBox $subject, $result)
    {    
    	if($this->_customerSession->getCustomer()->getGroupId()) {
    		return $result;    		
    	}else{
        	return '<h3>PLEASE DO LOGIN AND SHOW THE PRICE</h3>';
        }        
    }
}

3. Result