I agree with you there, but therein lies the great unknown about healthcare reform. If the government goes from being the 500lb gorilla in the room to the 1500lb gorilla in the room with a public option and/or growth of Medicare, the "market" is going to be predominantly artificially dictated by regulations, government reimbursement rates, etc. So free market economic theory goes out the window at that point because there is no "free" market --- there is only what the government says there should be, dictated by what it will pay for.
The easiest place to exert downward pressure on prices is at the provider level (note that is one of the major places Congress is talking about reigning in costs -- provider reimbursements).
I believe what other posters are probably referencing in terms of saying that if universal care passes, salaries will go down is the fact that in other countries providers make far less than they do here (Japan, UK, etc). Whether that would happen here of course remains to be seen, however with Congress wanting to slash reimbursement rates as their little budget panacea, I can't blame providers for being scared about it.
(Course I am just sitting here waiting for Japan to start selling off our short-term bonds and China's demographics to catch up with them in ~20 years ... talk about inflation. So long-term, I think any "entitlement" programs are moot, because IMO we are gonna be up to our eyeballs in inflation,and looking around saying "But but we're supposed to be the RICHEST country in the world!!! You mean ... you mean that was just DEBT?!?! But we iz sooooo specialz, that cannot be!!!")