With metro-aggregation being a domain between the core and the access network segments, where the main innovation drivers and requirements are high-capacity and low-cost architectures, respectively, it finds itself in a position where it is necessary to address both aspects simultaneously. Coherent digital subcarrier multiplexing (DSCM) in combination with a point-to-multipoint (P2MP) communication scheme offers the possibility to significantly extend the transceiver solutions sustainably. To demonstrate the potential of this approach, we carry out a techno-economic analysis on the basis of realistic, randomly designed, and flexibly configurable filterless metro-aggregation networks under different traffic growth conditions. Our investigation establishes a relation between the design characteristics of a network, its operating conditions, and performance. By evaluating the deployed hardware (i.e., transceivers) in terms of their power consumption, we demonstrate the advantages of optical aggregation and flexible allocation of bandwidth resources compared to full-capacity operation of DSCM-capable modules. Finally, a comparison to the operating conditions of traditional single-carrier coherent pluggables allows us to determine target specifications to manufacture competitive transceivers with DSCM technology.