In 2016, the battery pack cost is still ~$227/kWh, meaning that a 60kWh Tesla battery pack is ~$13600. The target cost for parity with ICE vehicles is $100/kWh, which is likely to happen sometime between 2025 and 2030.
This presumably assumes prices continue to fall at the current rate. However, the Gigafactory is no longer the only game in town, there are at least two or three other players in the process of spinning up battery production facilities of similar scale. Massive increased demand from not just EVs, but also residential and commercial energy storage, and eventually short-range flying electric vehicles, will drive the cost down much faster than the existing rate.
Disc space -- the final frontier!