Here's how my insurance works (BCBS, high deductible health plan through my employer): My deductible is $4k, my copay is 20%, and my out-of-pocket cap is $6800. So the first $4k of medical and prescription costs that I invite, I have to pay in full. They get filed with insurance, but I'm on the hook for the costs. The next $14k of expenses, I have to pay 20%, which at the point that my bills have hit $18k ($4k + $14k) means I've paid $6800 out of pocket. At that point, insurance pays 100% until the end of the year, when everything resets.
So, in January go visit my urologist. She bills $700 for the visit, but the insurance's negotiated rate is $200, so I pay $200 out of pocket. She writes off the other $500.
In March I have surgery. The hospital bills $11,000, the surgeon bills $2100, and the anesthesiologist bills $37,000 (I'm not making that last one up - that was the anesthesiologist bill from my surgery in May!!) The insurance knocks it down to $12k altogether through its negotiated rate (and the anesthesiologist has to settle for $2600 because of my insurance - poor guy has to do more work to make the payment on his Lamborghini.) I pay the first $3800 (since I already paid $200 toward my $4k deductible), then 20% of the remaining $8200, which is $1640. I've now paid $5640 out of pocket, and my insurance has paid $6560 (80% of $8200).
This continues until I've paid $6800, at which point the insurance pays everything. My medical bills usually run $50-100k a year (and sometimes as high as $250k), so I get to that point every year - last year it was in June, this year it was in April.
Confusing? Sure. And that's with made-up, round numbers. Throw in dozens of prescriptions, healthcare for a family of five, multiple doctor visits and procedures, lands here and there, and it starts getting complicated. That's the wonder of our US healthcare system, that it takes a lot of work and effort to keep track of all of this and all that labor does nothing to treat my medical issues. I've spent at least six hours on the phone in the last month (mostly on my employer's dime) trying to fix an issue where the insurance is still reporting that I haven't met my copay, so I've spent an extra thousand dollars or so just to get my most critical medications, and I've had to quit taking all my non-critical ones. I don't expect them to ever reimburse me for the extra money, which isn't in the $16k I budget every year for healthcare expenses. They've been promising for over a month that it's fixed, but it's not done yet.
Obviously I'm not the most typical case, but I'm far from the only one having to deal with this kind of complexity. It's remarkable that they can keep this accounting juggernaut working; when it breaks, I end up being the one paying for the failure, since I'm the one without lawyers on staff. But mostly it works, as long as I pump in the same amount of money every year as my mortgage costs.
So how much do these procedures cost? Nobody except the insurance company accountants knows.