When some people are starting out they have to take a lower hourly rate to compete with the overseas market.
This is why I ALWAYS say, it's NOT the amount that the freelancer charges that matters, it's the person's work ethic, skill set & communication skills that matter to me.
I've hired people at $10/hour that did WAY better than people who charged more.
So when ever any egomaniac tries to show off & tell me that they are the best b/c of what they charge, I tell them off. It's all smoke & a good sales pitch most of the time (not all).
And like jaagare stated, it also depends on how fast they work. Most overseas people don't understand English let alone what I want, plus they take double, triple & sometimes quadruple the amount of time a sharp English speaking people would take to do the task. Now this isn't always the case. There are plenty of English speaking people who don't understand the written word either & lie about their skill set, but that's a story for another day
If you found a great person for less, I'd say keep them & hide them away so you don't lose them, but every so often I'd give them an increase just to make sure they stick around.