Best Buy has a coupon for PlayStation Plus 3 month cards for $8.99 (half price). You must be a Reward Zone member in order to redeem the coupon. There is a limit of one coupon per reward zone member.
These are available in store only. I’d recommend phoning your local store before heading out to make sure they have some still. You could even get them to put a hold on one for you.
These cards apply to both the PlayStation 3, as well ast he PlayStation Vita.