Some recent comparison shopping suggests that WM does a great job of
marketing by cutting as deeply as they can on big ticket items while
keeping the margin pretty strong on the cheaper stuff we spend lots of
money on, but never bother to compare.

I needed to replace the nicad batteries in two Nicro Solar Day/Night
vents. WM wanted $15 for a "C" sized nicad.
I bought a pack of two at Radio Shack for $7.