Hah, after a quick google I see that the regular price is $60/year, with the typical "on sale" price being $50. So it's even more expensive than I thought.
The suggested retail price is $60 with non-sales prices being $50 and typical sales at $40 with rock bottom sales prices of $35/36. It used to be very common to find them at $30. The service is redeemable up to 3 years and they have no expiration dates. I would hope no one pays full suggested retail prices.
I stocked up early on the cheap codes, 8 years at $30 and 2 years at $36. My 10 year average price until the end of 2015 is $31.20 per year.