I found the Sonic Blue Rio CE2100(black)/CE2110(green) for $129.99 with a $40 Rebate at FYE this weekend. So that gives it a grand total of $89.99. And for a 2.5 GB Microdrive based mp3 player That is a great deal.
The CE2100 is basically the Rio Carbon with a smaller 2.5 GB Microdrive instead of the 5GB of the Carbon. The drive can theoretically be upgraded although I haven't attempted that. The one other thing it doesn't have is voice record capability. Again, i believe the microphone is there but it is disabled in the firmware, which begs the question, can we download the real Rio Carbon firmware to it to enable it?