How to change the variation title in the add to cart block in Drupal Commerce 1?
OK. I got it working. Perhaps not quite as simple as I'd hoped, but this function will do the trick ...

function commerce_price_attribute_form_commerce_cart_add_to_cart_form_alter(&amp;$form, $form_state) {
    if (isset($form['attributes'])) { 
        $entity = entity_load_single($form_state['context']['entity_type'], $form_state['context']['entity_id']);
        foreach (element_children($form['attributes']) as $field) { 
            foreach (field_get_items($form_state['context']['entity_type'], $entity, 'field_product') as $product) { 
                $product = commerce_product_load($product['product_id']);
                $status = entity_metadata_wrapper('commerce_product', $product)-&gt;status-&gt;value();
                if ($status) {
                    $items = field_get_items('commerce_product', $product, $field);
                    if (is_array($items)) {
                        $attribute = reset($items);
                        $attribute = taxonomy_term_load($attribute['tid']);
                        $items = field_get_items('commerce_product', $product, 'commerce_price');
                        $item = reset($items); 
                        $price = commerce_currency_format($item['amount'], $item['currency_code'], $product); 
                        $form['attributes'][$field]['#options'][$attribute-&gt;tid] = $attribute-&gt;name . ' - ' . $price;
                    }
                }
            }
        }
    }
}


Note that the $status value checks whether the variation is disabled and skips over it if it is - without that, disabled products were still showing in the list of options.