Silkworms are very good feeders and dead easy to raise.
Buy some eggs and hatch them in a sealed 600ml tub, in about a month from the start of hatching they'll be about 20-30mm long and a great size to use to feed hatchlings (about the same size as mealworms are).
I move my baby worms into a 4L sealed tub at about 3 weeks old to reduce overcrowding. (Overcrowding will result in lots of dead worms - when they have no choice but crawl over each other this will disrupt shedding and this causes them to suffocate.)
In about 8 weeks they will be big enough for each worm to a meal in itself even for an adult beardie.
Let some (maybe 20) form cocoons and become moths, every female moth will lay 300 - 400 eggs. You can set most aside in a zip lock bag or in a sealed glass sample bottle in the fridge til needed and leave some to hatch .
No more need to buy silkworms again , and maybe a tidy little money maker if you sell some eggs or worms.