When I consulted via a firm, they regularly billed clients $200-$300/hr for the work of developers and operations folks who were getting paid ~$20-25/hr.
Granted, this was in fly-over country, but the gap between billable-hour and developer-hour is quite often massive.
The upside of this is that their customers are used to paying those rates. If you are self-employed or work for a small consultancy you can undercut them and still make a bag of money.
can you? My experience has been that large corporations, never mind the government, are perfectly happy to pay 2x or 3x the rates in order to deal with someone large.
Granted, this was in fly-over country, but the gap between billable-hour and developer-hour is quite often massive.