If you have a stable nearby, go and get a bucketful of aged horse manure. If you have a paper shredder, shred enough corrugated cardboard to fill a tray. If you just HAVE to have coir, you can find it on line or at pet stores. Peat moss can be found at a home improvement store. But buying bedding is kind of silly. If you are determined to spend money, spend it on a good paper shredder.

Since you are probably going to feed your kitchen scraps to the worms, I would go with cardboard. Horse manure by itself already has a balance of C to N, so adding kitchen scraps will throw the balance off. But some horse manure or partially finished compost in the bedding will help the worms adjust to their new environment quickly.

Thank you, very helpful! I have easy access to all of those things. I still have some coir in the bin. It sounds like I can supplement it with a mix of peat moss, shredded cardboard, and compost - all of which I have on hand.