Shortcode for Compare Button

I would love to use this plugin with WooCommerce but I’m having some issues. My client is currently using WooCommerce as an online catalog so they don’t need the “add to cart” button. However if we don’t put in a price we’ve noticed that the compare button does not appear. Do you have a shortcode we can use to add the comapare button on the product page?

http://wordpress.org/extend/plugins/woocommerce-compare-products/