<?php $price = get_post_meta($have_post->ID, '_price', true); echo $price; ?> руб.
<?php
$args = array('product_cat' => '%categiry_name%', 'post_type' => 'product');
$loop = new WP_Query( $args );
foreach( $loop->posts as $have_post) : ?>
<div class="product">
<?php echo get_the_post_thumbnail( $have_post->ID, 'full', array('alt'=> $have_post->post_title, 'data-product_id' => $have_post->ID)); ?>
<a href="<?php echo $have_post->guid; ?>" class="product_name"><?php echo $have_post->post_title; ?></a>
<p class="product_info"><?php echo $have_post->post_content; ?></p>
<p class="product_price"><?php $price = get_post_meta($have_post->ID, '_price', true); echo $price; ?> руб.</p>
<a href="<?php echo $_SERVER["REQUEST_URI"]; ?>" rel="nofollow" data-product_id="<?php echo $have_post->ID; ?>" data-product_sku="" data-quantity="1" class="add_to_cart">В корзину</a>
</div>
<?php endforeach; ?>
Сделать можно просто добавив в соответствующий option атрибут disabled="disabled"
jsfiddle.net/n72d90ef