Lots of people were staying away from S100 because of the lens errors. That's why it may be in lower demand (besides the fact that is the older model now). Hopefully the lens issue has been rectified in S110.
The S110 does not have the lens error issue, fortunately. Also, anyone has an S100 with a lens error, Canon is well aware of it and will help you fix it (source [engadget.com]
Hope this helps,