This is becoming really popular on Themeforest these days. Buyers are using this trick to buy free templates. It happened with me three times
Step 1. Buy the template you need from the Envato market.
Step 2. Contact Envato support and tell them that you buy the template by mistake. You misunderstood that it is a WordPress Theme.
Step 3. Envato Support will reverse the sale for you.
Your template is free for you. Enjoy!
I am sharing this trick with all the authors to find a solution for this problem