You must use auto-renewal to get this price.
Benefits of auto-renewal:
# Well renew on your behalf, so you never miss an issue.
# The publisher wont send you renewal notices.
# Youll always receive the lowest price available at Amazon.com for your subscription term.
# Cancel anytime using Amazons Magazine Subscription Manager and receive a refund for any unshipped issues.
Learn more about auto-renewal subscriptions on Amazon.com.
I suppose you just need to remember to change it before the year is up