Cracking deal today over at Safari Books Online - an annual subscription for only $199, valid for the lifetime of your membership.
From the blurb:
This membership gives you unlimited access to over 30,000 books, videos, and conference talks curated with a single purpose - to help you learn new skills and advance your career.
Given I've been paying $39 per month, I'm sure you can guess that I've upgraded.
This was a 48 hour offer and I received the email some time during the night, so don't delay if you're interested.