About Medicare payments

I had a HIDA scan $4300. Had gallbladder removal last week. No clue what thats gonna cost. Have to pay surgeon, anesthesiologist, and for those inflatible leg things they use during surgery. I am on traditional Medicare and cannot afford a supplement. ETA had to pay $500 for facility fee. Not covered by Medicare

I'm worried about the costs. Medicare pays 80%. Anyone have surgery on traditional Medicare? Partner says I'll probably end up paying around$500. Any insight is appreciated. TIA