Select AmEx cardholders have a "spend $6 get $6 back" offer under Offers and Benefits online account that needs to be added to card. When you click on the link it takes you to a 6 month for $15 offer page. So net cost is $9 for 6 months for cardholders.
If you don’t have an AmEx card or the offer available to add you can still get the $15 promo price.
https://www.epixnow.com/offer/epixnow6month