Do you have a demo site where I can try the PRO version?

Yes, you can launch a demo site to try the PRO version here:

This will launch a brand new test install of WordPress for you, with WooCommerce and Coupon Affiliates PRO installed, along with some test data to help get you started.

The demo install will be available for 4 hours for you to have a look around, and give it a try!