You could try and maybe normalize salaries based on the location I guess, but this also hits a snag when you take into account occupation. Some occupations generally pay lesser than others. Do they then not warrant H1Bs? Don't think so.
If an occupation has a lower salary, then perhaps its time for the occupation to pay more to attract local candidates. Otherwise the H-1B is being used to suppress wages.
agree on normalizing for location, but not on occupation. If certain occupations require higher skills, and are therefore able to pay higher salaries, then I see nothing wrong with them getting higher priority.