I just stopped at the feed store looking for hardware cloth and they said they all use chicken wire with no problems. One guy said he had a raccoon get into the coop, but that was because he had a gap where he had stapled the wire on. And they had a 5ft x50ft roll for $50 - I haven't seen anything else that wide locally, I only need 14 ft for a floor and flat ceiling (maybe 7ft more if I do a peaked wire "roof") but if I can use it around the sides that would be good too (5x7 run, 4-5ft tall, and then a small piece maybe 2ft to wrap around the 14" tall legs of the coop, 11ft perimeter).
I did pay $50 for 4x50 coated 2x4 inch mesh - if chicken wire isn't good by itself, how about making the sides a double layer of the coated wire and the chicken wire (chicken wire on inside) so racoons (not that I've seen any here, but we must have them, something got our corn when we planted some a few years ago) can't reach through the mesh or chew through the wire? Even at $2/ft combined I think it's cheaper than hardware cloth.