It is possible to live in Manhattan for $70K/year--with roommates. However you should not have any financial shocks. You should not, just to name a personal example, find yourself suddenly needing three dental implants at $2700 each, not including the cost or surgery. You should avoid cabs and use public transportation instead. And you should avoid taking advantage of any cultural activity that isn't free.
One downside of taking lower paying jobs is that employers often decide that you really are worth the lower salary. Programmers can end up doing system administration and desktop work. Perhaps that's not too bad in moderation, but it's very easy to get sucked into an on-call mode. Then again there may be exceptional people who can program in their heads as if they had an office with a door they can close, while some administrative assistant is nagging about corrupted email.
Huh? There are literally millions of people in NYC getting by just fine in NYC making $70k or less. You're not going to live a white-bread suburban dream though.
The funny thing is, NYC has a great public transit system in Manhattan (and an OK system in the boroughs) and lots of access to free or cheap cultural activities. I grew up in Queens and went to the beach, dozens of museums, concerts, etc with my mom.
The vast majority of people, in all sorts of places, and at all sorts of income levels lack the ability to pay for a $15,000 dental procedure.
The same way anyone gets work done--during the day, he does easy shit, and if he has something hard to do, he does it at night and at home when he can't be bothered.
One downside of taking lower paying jobs is that employers often decide that you really are worth the lower salary. Programmers can end up doing system administration and desktop work. Perhaps that's not too bad in moderation, but it's very easy to get sucked into an on-call mode. Then again there may be exceptional people who can program in their heads as if they had an office with a door they can close, while some administrative assistant is nagging about corrupted email.