can someone tell me why? medical mayhem!

Ok, so I know that everybody's all up in arms about insurance companies, saying that they charge way way way too much and that some people can't get coverage, and that the government should regulate them, blah blah blah.
But I see it as the medical provider's (the doctors, the nurses, etc) problem, and here's why:

Eli just had several urological procedures, because he had E. Coli in his kidneys. He had to have a renal ultrasound and a VCUG - which is a very expensive X-Ray.

The "list price" at the doctor's office was
$693.00 for one part of the X-Ray
$230.00 for another part of the X-Ray, and
$335.00 for the ultrasound
_____________________________
$1,258.00

I think to myself, wow, that's expensive, but good medical care is worth it, right? Apparently I'm wrong.

I got a "deal" because I paid that day, which was 40% off, for a total of
$754.

I think to myself, that's a good deal, right? Apparently I'm wrong.

I just called the insurance company to see what my responsibility would be, because I figure they would cover a substantial amount of it. Here's what they said:

The price that my medical provider has agreed to accept from Aetna is the following:

$245, instead of $693, for the first part of the X-Ray.
$61, instead of $230, for the other part of the X-Ray.
$86, instead of $335, for the ultrasound.
____________________________________
$392.00

This number in bold is what the medical providers will accept for their services.

Why, can anyone tell me, will the doctor's office not accept this number from me? And why do we not call the HUGE upselling that they tried to pull on me FRAUD?

In these scenarios, I feel like faulting the MEDICAL PROVIDERS for overcharging, and for not listing their prices publicly (for all services, to all customers - insurance rates or otherwise), and for not being competitive in price.

And interestingly enough, having insurance only saves me $224 - MUCH less than my monthly insurance rate, and this was a pretty large procedure.

Please, someone tell me WHY we are looking at universal health care, when fixing this would be an obvious remedy?! And I'm looking for a logical answer here, one that reflects the questions posed given the information present. I'm not looking for "but but but we have to help the poor people, let me tell you a personal story."

GAH! This, my friends, is highway robbery.