The reason its expensive is because it a building that lasts until the trans-human era. It gets affordable around say medevil era. However if you can get it early it really will give your city a big boost.
As for redundant, I don't think they are redundant now since each require a resource to make (except for the dog breeder). Thus unless you have ALL the resources you are not going to have access to some of the other animals. For example I had no sheep, hemp or silk, but I had cows. In which case I built a yak farm and was able to make wool. I would like to have them have their own unique map resource however for now its limited to existing ones (ex. Monkey Breeder requires banana resource).