I googled it, e.g. "Since 2014, the cost of completed packs has crashed from $400/kWh to below $200/kWh for some stationary storage systems, he says. Similar reductions have hit the automotive market. GM has said it’s paying LG $145/kWh for the cells in the 2017 Bolt battery pack." http://spectrum.ieee.org/transportation/advanced-cars/2017-i... Several other websites mention 200USD as the price Tesla pays for the packaged cells.