You can buy Samsung INR18650-30Q (top of the line) off aliexpress in bulk for about $3 a piece. It's about 11 Wh.

You'd need 90 of these batteries to make a 1kWh pack, costing $270. Obviously this does not include casing, assembly, and BMS (battery management system), but that's an inexpensive (probably 10%) overhead.

Buying in "super bulk" and "from alibaba" would probably be even cheaper, and would probably approach $176/kWh.

edit: Check out Jehu Garcia on youtube if interested (no affiliation).