Surgery/dr bill seems insanely low

[XanaDUer2]

I have only traditional Medicare. I had my gallbladder removed 20 days ago. I was told by 3 reps the Dr cost AND surgery cost only $130 about. I had to pay $500 facility fee. Surgery was not in hospital but outpatient facility.

How can even common surgery Dr fee be that low? I can't seem to get an answer other than that's the cost. America is not like this. I pay 20%. I get it. But that low? I'm worried I'll get a big shock later