I've wondered about those. Will the chickens chew on the PVC vinyl coating, and if so how dangerous for them will it be?There is also now galved after weld with a PVC vinyl coat for about $200 for 20g 6'x150' and this I think is a really good buy if you think how long it will last.
There is also hard-wire PVC Vinyl coated welded after galvanized in 1" x 1" or 1" x 2" which is excellent for chicken runs and very predator resistant. For the 14 gauge 1" x 2" 100" long I've seen it available in PA are for under $400 per roll.