 <p>I followed that steps that pygorex1 posted but also replaced lines 191-195 in the <code>Select.php</code> file, because I was still getting another similar error about the <code>getPrice()</code>. I have Magento ver. 1.3.2.4. </p> <p>Original code from lines 191-195: </p> <pre><code>$result = $this-&gt;_getChargableOptionPrice( $option-&gt;getValueById($optionValue)-&gt;getPrice(), $option-&gt;getValueById($optionValue)-&gt;getPriceType() == 'percent', $basePrice ); </code></pre> <p>Here is the code I created to replace lines 191-195: </p> <pre><code>$z= $option-&gt;getValueById($optionValue); $result = is_object($z) ? $z -&gt;getPrice() : null; $zz = $option-&gt;getValueById($optionValue); $result = is_object($zz) ? $zz -&gt;getPriceType() == 'percent' : $basePrice; </code></pre> <p>FYI - I am NOT a PHP programmer. I just happened to figure out how to rework the code to make fix this problem based on pygorex1's code. So, there is a good chance I didn't write it correctly. However, it did fix the problem for me (which I am rather proud of :)</p>