Used to be a lot on eBay, but those are often overpriced. You have to know the new prices to be careful what you are getting into. But a new 20 lb. Lee pot
, at less than $70, is inexpensive enough that I would get that first and avoid used wear and tear unless the used pot was a better quality pot. Note that the RCBS and Lyman pots on the right side are several hundred bucks, by comparison. One of those used might be a reasonable bargain.
Lee also makes a $32 4 lb pot for ladle pouring, but you have to keep those topped up all the time. Hard to get production volume that way. You can also get a camping stove burner and a plumber's cast iron pot and learn to work with those.