You mean the little blue button on coolmaterial next to the price?
Thats just a standard button - depending on the theme you will be able to do it with some very simple CSS & code or maybe even a shortcode. Bottom line you just need to add any button nearby and add a link to it. Very simple
You would be best off to find a theme you like then get a freelancer to add the button if you cannot do it yourself easily.
Okay, thats what I figured I needed to do, but just wanted to make sure. Thanks for the help!