I would say $500,000 revenue, but I could support $500,000 gross income.
I don't see much reason why a company that makes $500,000 in net income a year should have to pay workers much less than what's proposed here. I could support making an exception for such companies if and only if they're in restructuring or losing money.
The purpose behind such a requirement is to provide a dis-incentive to businesses that provide menial and unskilled jobs to discriminate against older workers. So while it may appear as 'official' discrimination, it really seeks to prevent it in practice.
How, exactly, is the language at issue supposed to do this?