I am always a little bit flabbergasted by the developer salary numbers that get thrown around on HN but I think that the cost of living in NY & SF may skew the numbers higher than they are in the rest of the world.
edit: I am Canadian for reference and just Googling around a bit suggests anecdotaly that salaries are in the $50k-$100k range for most developers.
If you want to actually be able to save decent money in the US, you should aim for the second-tier (e.g. Boston, Seattle) or emerging (e.g. Austin, Pittsburgh, Baltimore, Portland, Durham) tech hubs where salaries are 80-90% of NYC/SV but cost of living is a lot lower.
NY and SV are good places to build your career, but most people who are intent on being lifelong programmers (as opposed to being managers or founders by 40) get out after a decade or so. The cost of living is annoying but bearable; the culture it creates, however, sucks because everyone is competing to be a manager or founder before being judged "too old". The cultural effects of high rent (much less purchase prices at 30-50 years) are even more of a travesty than those high rents are standing alone.
I'm coming up to ten years as a senior dev and I earn way less than the lower band of that Junior salary.