So you thought you'd just say it with no justifcation, investigation or evidence because it strengthened your argument?
You do know you're supposed to put the conclusion after the thinking, don't you?
You asked for proof, which I take to mean some peer-reviewed study or whatnot. I have all kinds of reasons to support my claim, and I've offered to go through them with you. I have laid out some of those reasons why ER prices are inflated and may not reflect true costs:
(1) Captive consumers who don't ask for prices before consuming services;
(2) cross-subsidization of other hospital services, since there is less scrutiny of ER charges;
(3) Inflating the cost of uncompensated care for the purpose of justifying price increases to the government and the public and for the purpose of getting more government money and private contributions;
I have also hinted at some of the reasons why ER prices should actually be lower than for regular, scheduled care:
(1) Extremely efficient use of resources by putting the burden of waiting on the consumers rather than the providers; triage especially increases efficiencies;
(2) Countercyclical usage patterns, so that most ER use is after-hours during a time when hospital resources are usually idle;
(3) Use of doctors being on call rather than at the hospital, so they can be doing something useful whenever there is less than expected demand.
Now, there are actually studies showing that ER prices have far more variability from patient to patient and ER to ER than prices for clinical care. I think this is evidence that ER pricing is more arbitrary, and in fact, opportunistic than for other hospital services. Perhaps there is another explanation though.
Now, how about you explaining why ER costs should be higher than for clinical care. Why should it cost more for a doctor in the ER to prescribe antibiotics for a sinus infection than for an office clinician to do so?