What is pax cost?

Could you please clarify what you mean by "pax cost"? This term isn't commonly used in the world of cryptocurrency or finance. Are you referring to a specific cost associated with a transaction, such as a fee charged by a cryptocurrency exchange or a blockchain network? Or is it a term used in a different context that you're trying to apply to the cryptocurrency and finance field? Without more context, it's difficult to give a precise answer to your question.