I'm thinking of starting a cricket farm

Actually I have learnt of an initiative where I come from involving the mass rearing of crickets to be used as food. They are quite nutritious and easy to rear. There is even an initiative to make cricket sausages with cricket flour being the main ingredient. The equipment required to rear them is very cheap and basically involves a bucket, a light source and a net. Quite a novel initiative though I doubt whether they would be pets in your case!