There is significant difference between telco-grade connections (i.e. T1, T3, etc) and datacenter ethernet drops.
Usually telco-grade connections have much expensive port cost at the ISP-end, as well as local loop fee to the telephone company. UCG however looks like they have a GigE drop from Williams and wireworks. gigabit Ethernet (or anything-Ethernet) has much lower port cost, and pretty much the $$$ part is just the pure bandwidth in bits/s rate.
UCG does not offer 50/mo plan anymore, unless they suddenly changed their plans again.. I believe the cheapest is 99/mo