This question is nearly impossible to answer and a very personal decision. Nobody here can tell you how much you are worth. For example, am I doomed to crap rates just because I live in the Philippines? No (sorry danohuiginn!)
Figure out how much money you want to make and how many hours you want to work. Remember that you cannot get eight billable hours out of an eight hour day.
As a "consultant" you are running a business. Asking other people how much your rates should be is not a business question, that is a programmers question. You are asking like this is some sort of algorithm you can plug into your code. You need to tweak your mindset a bit.
Edit: How to get consulting work.
Build your brand and visibility. Pick a community (get a bonus for picking one frequented by paying clients) and establish yourself as an authority. Create an open source project which you can point to which shows you know what you are doing.
Network! The area in which I am has more work than there are people available yet there is likely no shortage of people who would love to break in. The reason for this paradox is that I only work with people in my network.
All the freelancers I know are overworked. Often any one of them need help and I can't help them because I am overworked as well. Get to know other developers who are freelancing and ask them if they know anyone who needs a hand.
It's all about that recognizable and trusted brand!