I’m guessing you already saw this – http://appfinite.com/topic/how-to-add-the-plans-features/
If you notice the part that says – <div class="plan-button"><a>Buy Now</a></div> you can add a link inside of it like this –
<div class="plan-button"><a href="http://add_you_link_here.com/">Buy Now</a></div>
I changed the first <a> to this – <a href="http://add_you_link_here.com/">
I create awesome sites for awesome people! Contact me if interested – ericsanchez1585@gmail.com