My recent experience with Elance in particular, seems to suggest that there are a lot of developers based in Asia who are prepared to undercut western developers to get the work, but they all seem to target the popular technologies, such as PHP and C# development. As soon as you move into less popular technologies you start to find fewer people bidding, and those that do are prepared to pay much more.
A friend has used Elance a number of times to find work. One job was testing applications to ensure they were suitable for use by children, and she was being paid more for this than she earns in her day job.
I have posted a few jobs on Elance expecting to be flooded with cheap offers of $5 an hour, but received no such thing. These were jobs involving web design and an iPhone application involving voice communications. In the first case I received offers far higher than I was prepared to pay, and in the second I received no bids at all.
In both cases I would have been happy to except a reasonable offer from a quality developer rather than the cheapest offer, but in both cases I simply was not receiving these.
I think you can make money freelancing on Elance, you just need to specialise on a less popular field so that you are not competing directly with the Asian developers.