Tier pricing is great, but you don’t want to display every price to every customer. To show tiered pricing to logged in visitors only, go to:

app/design/frontend/default/default/template/catalog/product/view/tierprices.phtml

 On this file, add this PHP function

<?php if(Mage::getSingleton(‘customer/session’)->isLoggedIn()): ?>

 The above function should be added before the following piece of code

 <?php if (count($_tierPrices) > 0): ?>

Then add this code at the end.

<?php endif; ?>