I think it's OK to change salaries based on where you are. If I live in NYC or SF then a salary of lets say $120k won't be enough of will barely be enough because of cost of living, but take that pay to somewhere like Denver or Atlanta and all of a sudden that $120k will buy you more than you ever could in NYC/SF.
So I feel like pay based on where you live is OK. At the end of the day if you want to draw talent from costly cities then you are just going to have to pay them more or else they won't be able to afford to work for you.
It's not John is more qualified than Jane so he gets an extra $50k a year. It's John has 4x the monthly rent that Jane does so without the extra 50k he can't even take the job.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.