if you start with enough, and have the time for it, its a great way to save money. my bug breeding projects take up my room, i have a tub of breeding roaches, and a tub for crickets, but i transfer the cricket eggs to a ten gallon to hatch, silkworms do not take much room, i use a cake container XD id like to get into mealworms soon, but it takes them months to grow to a size they can be fed off...so it all depends how many animals you have. if you have one or two, buying from a retailer isnt bad, but if you have more, id say breed