It’s actually the opposite.

My xray was $1000 with insurance, but my co pay was $100.

I asked how much the cash price is without insurance and the xray was $100.

Medical procedures are 90% off of you pay cash.

Usually I see things like the doctor billed the insurance $1000. The insurance paid $300 and said I had to pay $100. The remaining $600 goes unpaid, and the doctor never expected to get it
I see this also. My insurance in 36k a year for a family of 4. I would be better off paying cash than paying for insurance. Currently going to the doctor for the 4 doctor visits cost me 9k per visit plus $5 co pay. Cash would cost me $50-75 per visit.