For this month only, you can get the yearly membership option on this site for $30 a year. That’s a $10 savings right to your wallet.
(Also, you are welcomed to upgrade from monthly membership to yearly and get the $30 price. Just cancel your membership, stay logged in and go to the join page. Select the new membership and enter the info asked. You should now be rolled over. However you won’t get a refund for any partial month stuff.)