$250k/year is probably twice the median salary for a developer in SF. Yes it's not quiet the same as it would be in India, but still is pretty good. I personally would take it, just because I feel it's a better place to live and work.
To put it into perspective, Google pays it's CFO a base salary of $650K a year. Of course there are bonuses, and stock options that make it much more than that, but I doubt you'll get anywhere close to what the converter says.