Norton is offering their Premium security suite for $35 before a $20 Visa card, bringing the final price to $15.
There are some key differences between Premium and Deluxe. Premium offers ten installations instead of five, and very well-reviewed parental controls that are not available in Deluxe. Premium also offers 25GB of cloud storage which is...nice I guess? If you don't have Dropbox or similar.
This is currently the best price for Premium, so if your use case includes lots of Windows or Android devices, or teenage kids, the additional features may be useful. (They do have an iOS version included too but it doesn't garner the same glowing reviews.)
Link to download page [nortonsecurityonline.com]
That page has both the $20 rebate which applies to all their versions, and further down it has the discounted Premium. Rebate requires proof of previous product - it is an upgrade or competitive rebate. Proof is easy.
Two major caveats - first, the subscription starts immediately. Second, it enrolls in auto-renew, but that's easy to cancel here. [norton.com]
Cancelling it immediately does not do anything to the current subscription, just drives home the point that retailers can be unpleasant.