[Update: Retail availability dates added to the story below.]
Earlier this year, Microsoft introduced a new way to score yourself an Xbox 360: cheap, but with an annual contract. You could get a 4 GB with Kinect for just $99, but you'd have to sign up for a two-year contract. This actually meant you'd be spending more in total, but in smaller, more manageable chunks. Microsoft is now expanding the idea to include more configurations with much bigger hard drives.
The Entertainment for All plan (via Kotaku) offers a 4 GB Kinect system for $99 as usual, along with a 250 GB without Kinect for $99, or a 250 GB with Kinect for $149. Each of them, of course, requires a two-year subscription at $14.99 per month.
The site notes that these retail configurations are coming soon, according to a post on the Major Nelson blog. GameStop and Toys R Us will get the new configurations on October 28, followed by Best Buy and Wal-Mart on the 29th, and Microsoft Stores on November 5.
It's still cheaper to buy an Xbox 360 at its regular price point, of course, so if you have the cash and want to save money that's the preferable option. But if you've balked at paying hundreds of dollars all at once, this option might be a little more palatable to you.