For those couldn't jump onto Headspace freebie (or couldn't bring themselves to use up the license of someone else in need) Headspace just emailed me with an offer for a subscription with 5 months free. Might be a targeted offer for people who have done the trial but haven't signed up.
Note that this is billed annually.
Edit: PennyPacker has pointed out below that it might be only for those in their final 30 days of subscription. I dunno how strict that is since I have only ever done the trial and that was a few months ago. YMMV