Notice how for the US the article doesn't even mention the upper bound for specialists. That's because there is none, and they expect that.
GPs are quite affordable, if it was just the GPs I wouldn't mind paying them $200-300 directly for a visit. But the specialists can really get you crying for mercy, especially if there's no insurance company between you and them.
I broke a leg a few years ago, and if I did not have insurance, the cost to me would be $55K (probably more, this doesn't count the follow-up visits). Surgery alone was $30K+ for about 2 hours of work, not including cost of anesthesia ($5K). Insurance got the total down to about $7K, which is still a lot of money for a relatively run-of-the-mill surgery. Cost to me was my deductible: $1K.