Before i went on Medicare i would tell the receptionist i was self pay and ask if there was a discount. In all but one fase the discount amounted to anywhere from 10 to 80 percent of what they charged the insurance. I had kudney stones surgically removed about one third their billing rate. Ran about 4k. The differece is they get the cash now as opposed to next year sometime.
Back in the day, I had a physican as a good and regular customer. I had to go to his office to get payed, he did not respond to mailed invoices.
I went one day to collect and his nurse held up the cigar box..... “No cash in the till today”
He payed his service providers in cash that was ever registered on his ledgers