Switch from Monthly to Annual payments and get 2 months knocked off the pricing for the year. Follow these steps to upgrade.
Click your name in the top right of your account.
Click Account Settings.
In the dark blue box on the right, click Switch to Yearly.
Check the preview of charges to make sure you are happy, then click Proceed to Checkout to pay.
Note: If you have already paid for the month, your remaining part of the month will be prorated and knocked off the price. You will be charged immediately upon completing checkout.