I was able to pick up this Vader at a Walgreens on my way home from work today. I only saw one, but it was good to knock this off my list.
But a general note if you are looking for these? Check the end caps, because that's where I found mine, not in the regular toy aisle. Most of the Walgreens stores in my area still have a dedicated Star Wars end cap, and I get the sense that Walgreens has a directive to place this exclusive Vader on those end caps.