Hi Hi @JohnWick, welcome to the Discourse! 
This is a friendly place to chat and ask for help on CodeCombat levels (remember to format your code correctly). Before you continue, don’t forget to read the guidelines here if you haven’t already.
We hope you enjoy your time here! 
Unfortunately it is no longer possible to buy gems in CodeCombat.
However, as Anonym said in this reply, you do gain gems for becoming a subscriber.
Hopefully this helps to answer your question,
-Marmite