Commission based salary?

I am having issues with my pets doctor being paid on a commission basis, the business manager got angry with me when I confronted them with this issue and why there prices were so astronomical, what I got as an answer was that they strive to be the best. I have an ethics issue with them being paid a commission. I want them thinking about my pets best interest not there personal bottom line. Would you have an issue with this? Would you worry about them selling you products or procedures your pet may not need? Diagnose an issue and maybe decide on one treatment instead of another because of the money issue and because it works better for them rather than for Your pet. How do you feel about your pet working on a commission based salary?