You couldn't find the specific control for the price in that page because there is none. The Column Grid mod in column mode collapses all the elements of the product into one, and any parts that don't have a separate handle like <h3> or <a> are indistinguishable.

What you can do is increase the font-size for the whole product and then reset the link and heading as desired:

.centerBoxContentsProducts {font-size: 1.2em;} /*general*/

.centerBoxContentsProducts a {font-size: 1.1em;}/*more info link*/

.centerBoxContentsProducts h3 a {font-size: 1.1em;}/*title*/

Adjust to taste.