I don't know. Sleep Cycle works well about 94% of the time for me. With an improved wake algorithm, I think you could pull it up to at least 98% of the time in pure software, or at least that's what I got for my sleeping patterns playing around with the data in Mathematica.
Is improving 2% of your wakeups worth $48? Your wakeups would have a "valuation" of $2400 by that logic. Which, I dunno, maybe it should, but it seems a little high.