Home Depot is selling a single 6Ah battery for $129, this is 2 batteries for $59.50 each. Free S/H.
https://www.homedepot.com/p/RIDGID-...h-6-0-Ah-Battery-2-Pack-AC8400806PN/301404326
Also 2-pack of 9Ah batteries for $179 ($89.50 each):
https://www.homedepot.com/p/RIDGID-...-High-Capacity-Battery-2-Pack-AC800/304829433
And 4-pack of 9Ah batteries for $349 ($87.50 each):
https://www.homedepot.com/p/RIDGID-18-Volt-9-0-Ah-Lithium-Ion-Battery-4-Pack-AC804/304740784
https://www.homedepot.com/p/RIDGID-...h-6-0-Ah-Battery-2-Pack-AC8400806PN/301404326
Also 2-pack of 9Ah batteries for $179 ($89.50 each):
https://www.homedepot.com/p/RIDGID-...-High-Capacity-Battery-2-Pack-AC800/304829433
And 4-pack of 9Ah batteries for $349 ($87.50 each):
https://www.homedepot.com/p/RIDGID-18-Volt-9-0-Ah-Lithium-Ion-Battery-4-Pack-AC804/304740784