I watched that video a few days a go. Like you I dont want to pay for something so simple. I bet you could make this out of plexiglass. Plexi is easy to work with. just score it with a razor knife and give it a good swift hit while hanging it over the edge of the table and it breaks right on the line you scrored a few times. You could enlarge this pattern to almost any size with your printer.
http://quilterscache.com/T/TumblersBlock.html