I know that Mulberry Farms (http://www.mulberryfarms.com/) sells them, and I've ordered them from Linda's Gone Buggie (http://www.lindasgonebuggie.com/). I think it depends on where you are located. For me, Mulberry Farms' shipping is ridiculous, and Linda's Gone Buggie is much cheaper (and she's really great to work with). She also offers value packs that save you a bit of money, and you can try different types of feeders to see how your beardie likes them (and variety is always best for your beardie). I'm sure there are other places to buy silk worms, but those are the two that I'm aware of.