I don't think metro construction projects in Moscow are particularly cheap. But building extra stations makes a lot of sense due to scale and concentration. Mo

I don't think metro construction projects in Moscow are particularly cheap. But building extra stations makes a lot of sense due to scale and concentration. Moscow metropolitan area represents 1/5th of Russia's GDP and 1/7th of countries population. A new station in Moscow potentially benefits a higher proportion of Russians then, say, a station in NYC for Americans. Moscow is also one of the most congested cities in the world (n.1 in 2020 https://www.tomtom.com/en_gb/traffic-index/ranking/ https://www.tomtom.com/en_gb/traffic-index/ranking/). Expanding public transport is probably the only way the city can sustain itself. Also, metro is extremely popular among the population in general. Building new stations and lines is a crowd pleaser and voters winner. AFAIK lack of widespread public support is the reason many public transportation projects fail in the US.