Prodnography: Levenger Circa Junior Notebook (review)

I've always been leery of notebooks with proprietary pages that you have to buy from the same vendor or a specialized stationery or office supply store. I used a Franklin Planner for a couple years and loved it, but I eventually got tired of making special trips to buy refills. Are the pages for this notebook a common size that you could buy, say, at a convenience store like Walgreen's? That's why I always come back to simple things like index cards, because you can buy them anywhere.