Two of the larger suppliers of candles and lamp oil for churches have unionized workforces.
Since I also like sole proprietorships and cooperatives, add them in the comments if you know of some, particularly if they make candles in pure beeswax or soywax. Refurbishers of church furnishings, too.
Later. I guess there's no more practical example of a cooperative enterprise than a monastic business, and all (or practically all) Orthodox monasteries earn their own keep. Many make pure beeswax candles, and most sell them by weight. $10 a pound seems to be a fair price for thin tapers and $7 or $8 a pound for thicker tapers and for table-top or altar candlesticks. (I've noted the Orthodox monks don't get worked up about the "secular" use of "sacred" candles, and plainly sell them for household use, too.)
I would recommend to all who have Christmas Eve or Easter Vigil candlelight services to use thin pure beeswax candles. They aren't really that expensive for what you get: clean, gently sweet, and virtually drip-free burns. That's good if you've ever been to service in a darkened church and have had a paraffin-stearic acid candle drip down your wrist. Those little paper flanges (called bobaches) do little good. Get the quarter-inch or three-eighths inch tapers, nine or ten inches long.
Orthodox Church of America -- formerly an ethnic Russian church -- monks seem to have better prices than the Greek or Roman Catholic monks.
Two examples, one on each coast:
Saints Mary and Martha Orthodox Monastery -- halfway between Columbia, S.C. and Augusta, Ga.!
Monastery of St. John of Shanghai and San Francisco -- in Point Reyes Station, California -- is that Marin County?