I suggest reading this reddit post about hospital billing [1]. You certainly have options other than paying a shitload or leaving your arm untreated. Money can be negotiated, but you only get one body.

Edit: I see elsewhere in the thread you have health insurance. If you're paying for it, utilize it. You're in a better position to deal with this than uninsured people.

[1] https://www.reddit.com/r/TrueOffMyChest/comments/x9b7vm/im_p...

Joints are critical. I can't judge without knowing a situation, but I wouldn't want to live my life with a fucked up elbow because I didn't go to the doctor.

When I was briefly without insurance between jobs, I went on a desert hike and was scared about getting injured, so I get it.

Your untreated joint injury has a strong chance of winding up much more expensive later, especially if you develop chronic symptoms that make it difficult to work.