Don't really want to argue this much, because I mostly agree with you on that, little bit of devil's advocate i guess, and its not really the main topic here, but the risks are completely different. Human life has a lot more value than an animal's does. I would also give all the money in the world to have my son be healthy, but with an animal there is a line.
What is comes down to basically is Doctors can charge more because they can get away with it. I would do the same thing.