Any ideas as to what the true market rate for these types of jobs is? Theoretically, if BART did not have a union, would we expect it to be filled with minimum

Any ideas as to what the true market rate for these types of jobs is? Theoretically, if BART did not have a union, would we expect it to be filled with minimum wage or $40K type salaries. Any other thoughts into how much labor costs as a proportion of their total expenditure. Is this where BART needs to decrease spending the most?