title: Trying to calculate sales tax on an individual item in Magento without displaying prices including tax
body: <p>Magento CE ver. 1.7.0.2</p>
  
  <p>I'm trying to grab some order data from our Magento store to integrate into our other business software.  In my case I need to compute the price plus tax on individual items.  The below code only works if <strong>Display Product Prices In Catalog</strong> is set to <strong>Include</strong> or <strong>Both</strong> (in System > Configuration > Sales > Tax).  How can I calculate the tax on an item while still having the website display prices excluding tax?</p>
  
  <pre><code>$customer_tax_class = Mage::getModel('tax/calculation')-&gt;getRateRequest()-&gt;getCustomerClassId();
  $_product = Mage::getModel('catalog/product')-&gt;loadByAttribute('sku',$skunumber);
  $my_price = Mage::helper('tax')-&gt;getPrice($_product, $_product-&gt;getPrice(), true, $shippingAddress, $billingAddress, $customer_tax_class);
  </code></pre>
  
  <p>I also tried using this instead, but I still get prices without tax (unless I change display settings mentioned above):</p>
  
  <pre><code>$_finalPriceInclTax = Mage::helper('tax')-&gt;getPrice($_product, $_product-&gt;getFinalPrice(), true, $shippingAddress, $billingAddress, $customer_tax_class); 
  </code></pre>
  
  <p>I know it must be possible, as Magento figures out the tax when you place the order.  Any help would be greatly appreciated.</p>