I'd stress adding a sample for each grade, if possible. It makes it easier for your prospective buyers/subscribers to imagine what starting this program might look like, since most will be looking, initially, at a single grade or a few grades, not the program as a whole, and 6th grade, say, can be a whole lot different from 2nd grade. Avoid making them try to guess how the form and content for a lesson for a grade they're not (currently) interested in will look for a grade they are interested in.

Super bonus points if you can record a couple of the lessons being delivered and post them on Youtube or whatever—the more you can convince prospects that they can use this and have it actually work, the better, I'd expect, and videos can help fill in gaps in imagination or confidence in turning written materials into a real lesson. Kinda like how sometimes a YouTube video of a board game with complex rules being played can make one more certain about how to run it, than reading the rules a couple times.