I assumed the extra cost was not because of the unrestricted bandwidth (Granted I have Xfinity in Chicago and only pay $15 a month for unlimited on Gigabit)but because of the static IP(s) associated with the service. In addition I would assume that trouble calls are elevated over that of a home user with quicker response times.

Just looking at Biz service vs home and assuming that's because of unlimited bandwidth is 1:1, there's more going on there that's different between the two.