I came across this link which lists in detail every H1B petition filed by an employer over last few years. One interesting thing is that they list the actually wage offered by a company for a given position to the beneficiary of each petition. This perhaps a more accurate representation of salaries in Tech industry than the glassdoor review.
As someone who has gone through this process, I'm sad to say the petition can have a 'projected' salary. So it's just as fudged a number as any. It holds no bearing on what the worker would truly get.