Home Depot has RYOBI ONE+ 18V Lithium-Ion 4.0 Ah Battery (2-Pack) with 18V Charger for $79. Shipping is free.
https://www.homedepot.c
Also available, ONE+ 18V Lithium-Ion 2.0 Ah Compact Battery (2-Pack) with 18V Lithium-Ion Charger, $59
https://www.homedepot.c
RYOBI ONE+ 18V Lithium-Ion HIGH PERFORMANCE Starter Kit with 2.0 Ah Battery, 4.0 Ah Battery, 6.0 Ah Battery, Charger, and Bag, $149
https://www.homedepot.c