Similarly for the batteries. If lithium-ion could be had for $0.26/kWh then a Tesla Model S battery would be $26.
As it stands, Tesla batteries are estimated to be around the $100/kWh level for individual cells and projected to fall below $100/kWh at the pack level in a couple of years [1].
Capital costs are in the 100s-1000s dollars for kw of pumped storage.[0]
[0]http://large.stanford.edu/courses/2014/ph240/galvan-lopez2/