Usually a contractor charges from $150 - $200/hour, with a discount if you need them for more than a couple weeks.
Also keep in mind: A day rate implies consultant (i.e. non-employee) work, which further implies <100% utilization. Assuming he only works weekdays and takes 4 weeks of vacation (comparable to working at a BigCo), 80% utilization gets you to ~192 days, or $210k.
That's probably optimistic, though. This math further assumes he is able to sell 80% of his time in the 20% of his nonbillable time, and that he doesn't lose any billable time due to scheduling issues (i.e. each client is ready to go as soon as he is). Depending on his business, he'll have to spend some cash on overhead (accountants, lawyers, etc.).
Under utilisation is true enough, but you also have to take into account the tax efficiencies you can put in place as a freelancer (in the UK at least), which means he's still well enough off to have a Porsche 911 and a flat in the Swiss Alps.
Nice work if you can get it.
However, I'm also not denying that there are many highly influential, priceless, people getting paid these high salaries that are greatly beneficial to our society and have legitimately earned their fortunes. It's just unfortunate that everything is being done to support the continuation of rich getting richer and poor getting poorer. However, thanks to some people, the entire world can become richer.
Most good Java guys that I know take around £500 - 700 per day in the enterprise, telco, banking and ecommerce space.