As mentioned, Olomana Gardens sells composting worms, vermicast, vermicast with eggs and worms, and large burrowing worms. His farm produces worms and vermicast everywhere on the farm. in his grow beds, under his
chicken coupes, and in bins. He has an abundance of worms from years and years of raising them. I visited his farm and i saw at least a dozen 50 gallon totes filled to the brim with pure vermicast. He also sells numerous things grown on his farm.
Another lady in Honolulu has a
workshop to set up a worm
compost bin she also sells the worms and vermicast. At the time it was $30 you get 1 ounce of worms and a small plastic pot to put your worms in to start you compost bin. She teaches you how to care for, raise, and harvest worms and castings.
So yes it is possible to make an income, yet it looks like some time may be needed to build up a supply of worms without wiping out the population selling them all.