Negotiating Self-Pay no insurance bills?

Has anyone had any luck negotiating self pay surgery / ER bills in the United States? I know there are financial assistance forms where you can get a discount or even all of the debt wiped. The problem is that my income swings drastically being self employed and last year was a good year but this year will be very low and previous years were very low. The form just cares about prior year and wants bank account information. I have heard of some people calling and getting 50% discount if they say they can pay it all at once if they can discount it 50%. Anyone here get a big discount?