There is only one way to know if a company is paying "too much" (i.e., more than it has to to attract qualified labor) or too little. If there are significantly more job applicants than there are jobs, then the company is overpaying. If it is having trouble attracting and retaining qualified employees, it's probably underpaying. There is no objective measure of "the right pay level."
That's why the following headline from the Jan. 25 Crain's Chicago Business is so interesting:
"Wal-Mart gets 25,000 applications for Evergreen Park store."
That's 25,000 applicants for 325 positions that average about $11/hour in pay for entry level, non-management employees.
Last year an Oakland, CA store got 11,000 applications for the same 325 jobs.
Link.