Price on Request

Hi,

I'm not sure this is what you want but I think that you can do what you want with the "Display a contact button on the product page" option which is available in the commercial editions in the tab Display of the config. That will add a contact us button on the product page. Then, if you don't set a price on the product, you won't have the add to cart button and you can change the text "Free" to something by overriding the corresponding translation key like that:
www.hikashop.com/download/languages.html#modify