All over the map (sorry, bad pun). It depends on where you live, who you work for, what technologies you work in, and (more than any of the above) your skill in marketing yourself to the right clients.

I have personal knowledge of folks who do software development at a range of price points between $25 and $200.

I assume that rate is per hour?

For what's it worth, in Western Europe I'd say 75 euros/hour ±50% is what you can expect for usual "Enterprise" fare.