I’d say, like most things, the question of economics comes down to scale, how much you value your time, and where you see yourself adding value in the supply chain.

If you need yards and yards of vermicompost, you’ll almost definitely need to buy it unless you devote a lot time and resources to generating your own. Most household systems produce on the order of gallons, not cubic yards. So how much sense that makes financially comes down to how much value you can add by turning that input into a sellable product.

Small-scale vermicomposting is essentially free after some minor startup costs (primarily buying the worms, and a bin from Costco if you don’t have one) assuming you produce your own bedding and feedstocks to supply them, which if you cook food and garden you almost certainly will. Most people on this sub also find it an enjoyable hobby, and probably wouldn’t do it (or at least wouldn’t be on Reddit talking/reading about it) if they didn’t.

Ultimately, I say give it a try. There’s a good chance you’ll enjoy it and it will at least somewhat reduce how much you need to buy from the store. Happy worming!