I can potentially use enough of it that I wouldn't want to drop that kind of money. But I've used those as well, and they do work very well, as well as tinderquik tabs. Even buying in bulk, I've got better things to spend money on. Unfortunately despite all the other invasive species here in Australia, birch isn't one of them. There are some trees that do have useful bark, but we have a strict ground-deadfall only policy, otherwise every tree would have all the branches below six feet ripped off. But a dozen or more kids picking up every twig that's fallen gets a good size pile of wood in pretty short order, and they think its fun.
In the past I've used everything from a dixie cup full of metholated spirits (very cool delayed ignition, so you kind of "magic" up a fire), to an 80,000 BTU roofing torch to get a fire going, it all depends on the circumstances, and tools at hand, and the overall goal. Also, as I get more experience teaching groups, I'll be much more able to tailor the overall experience to their interest and skill level. I think with some of the older groups, things like steel wool would be good, and sometimes I'll be able to do one-match challenges and the like. It all comes down to the time allotted and this is just one more tool in my kit that I can use.