Some Home Depot locations have the 2-pack of Ridgid 4.0Ah batteries (Model AC840087P) available for $79. Typical price appears to be $198, or in the $150 range on sale.
I'm seeing this in Issaquah, WA available for immediate pickup. Unfortunately it's not available for shipping, and when I change the store to my local store in Oregon the price goes back to $198. Might be a good deal for some!