Paris spent 1.3B euro on the 14 line, which has 9 stations. The MTA spent 2.4B on a single stop on the 7 line. MTA construction costs drastically exceed worldwide norms - the MTA spends $1B/kilometer.
http://www.systra.com/IMG/pdf/metro_meteor_en.pdf
https://pedestrianobservations.wordpress.com/2013/06/03/comp...
Apparently the only project outside NYC to cost more than $1B/KM is London's Crossrail. Even the Jubilee line extension is only $0.45B/km, and that's pretty pricey.
https://pedestrianobservations.wordpress.com/2011/05/16/us-r...
tl;dr; Funding is adequate, costs are simply out of control.