An initial analysis of 5G has shown that it is a radical departure form the generational trend: In particular headline rates and capacities which are X10 and X100 greater than the improvement attained with previous, more evolutionary, upgrades. In order to achieve these metrics will require extreme densification of the network given the spectrum that is available for 5G. A compelling case is made that this densification will cause costs to balloon. To access this costs a techno-economic analysis of the 5G eMBB (enhanced Mobile BroadBand) scenario in dense urban areas has been accomplished by radio capacity modelling of probable 5G technologies within a 1km² grid representing central London. Different density networks were modelled at: 700MHz (macro network), 3.5GHz (micro network) and 24-27.5 GHz (hot spots) – together with 802.11ac access points. Using published data on network costs various deployment options have been evaluated for capacity, headline rate and CAPEX/OPEX. It has been shown that reaching headline rates of 64-100Mbps everywhere is possible with a number of different technology options. Massive increases in capacity (in excess of 100Gbps/km²), however, can only be realistically achieved with millimetre wave (outdoor) and internal base stations The cost of deploying such capacity, however, will be several times that of LTE – we estimate a 4 to 5 times increase in costs for a 100Mbps everywhere network that has x100 capacity increase over existing LTE networks. One possible way of reducing the costs of 5G and increasing capacity is to place femto or distributed base-stations within buildings: we have demonstrated 3Tbps/km² of capacity with 5,800 femto cells per km² for a neutral hosted solution. However, there is a substantial up-front cost to utilizing internal base-stations: fibre back-haul and internal fibre needs to be installed. This initial cost is identified as significant barrier.