> always wait for a sale or deal and get the batteries free with tool

I agree. I don't think I've ever paid full price buying a battery by itself. I just can't stomach the terrible value. I watch for a sale and pick up a new tool with the battery I want. I've got a few relatively obscure tools that way that I'd probably not bother purchasing otherwise.

It's price segmentation - they know that a contractor/employee who needs a battery ASAP will pay sticker price, whereas homeowners will wait for a sale.