Do you know what they are testing for?
If they are PCR testing for multiple things, those labs can be expensive. I have a cat with chronic uveitis, and for exam and uveitis panel, which covers a fair amount of possible causes (PCR) my bill was over $800. Most of that was for the labs. It totally sucks that it cost that much, but it's, sadly, the reality, particularly if you have to see a specialist. We had an emergency visit that was just under $2000, for the same cat, all to hopefully preserve her vision. It is suspected that her issue is autoimmune, so all testing is basically to rule everything else out, and so far that is what it looks like.
So I completely understand where you are coming from. It's always a personal decision, particularly with a chicken, whether the cost is worth it. I would never try to decide that for someone else. Many do not seek vet care for their birds for that reason, be it right or wrong.
And depending on the practice, the doctors themselves may have no, or little, choice in what they can and can't do. Some of the larger corporate practices are more about the bottom line. Sadly. I have a family member that was a vet tech for one of them for a while, and will never work there again due to their practices. But there are some good ones out there, you just have to find one, if there is one close enough. When it comes to birds, the choices are much more limited.

If they are PCR testing for multiple things, those labs can be expensive. I have a cat with chronic uveitis, and for exam and uveitis panel, which covers a fair amount of possible causes (PCR) my bill was over $800. Most of that was for the labs. It totally sucks that it cost that much, but it's, sadly, the reality, particularly if you have to see a specialist. We had an emergency visit that was just under $2000, for the same cat, all to hopefully preserve her vision. It is suspected that her issue is autoimmune, so all testing is basically to rule everything else out, and so far that is what it looks like.

And depending on the practice, the doctors themselves may have no, or little, choice in what they can and can't do. Some of the larger corporate practices are more about the bottom line. Sadly. I have a family member that was a vet tech for one of them for a while, and will never work there again due to their practices. But there are some good ones out there, you just have to find one, if there is one close enough. When it comes to birds, the choices are much more limited.
