Amazon is currently listing the 110 for $38.24. Free standard shipping. No expiration shown. This is less than the 100 is selling for.
I just noticed the OBi110 Voice Service Bridge and VoIP Telephone Adapter was on sale today (11/20/2012) for $36.99 & this item ships for FREE with Super Saver Shipping!!!
http://www.amazon.com/OBi110-Service-Bridge-Telephone-Adapter/dp/B0045RMEPI (http://www.amazon.com/OBi110-Service-Bridge-Telephone-Adapter/dp/B0045RMEPI)