Here is a simple heuristic that's worked well for me: look at all of the job ads online for similar roles in the same city. Most will not name numbers. Find the highest listed number (top of range) in all of those ads and add 20%. That is a place where you will not be selling yourself short. You may not be maximizing your comp, but you will be above the average. Just understand this may disqualify you from jobs where they only pay below average. You need to be comfortable with being disqualified for high comp.
In addition to highest published umber + 20%, I would advise to carefully read any stated salaries on message boards like this when they come along and pay attention to the highest numbers. Then you will be aware of what is possible.