It seems those prices aren't available.
To avoid being misleading @AwesomeForo I have edited the price to $17 which is the price of a 12 month license (and updated the updates duration field from 6 months to 12 months).
To avoid being misleading @AwesomeForo I have edited the price to $17 which is the price of a 12 month license (and updated the updates duration field from 6 months to 12 months).