I looked at low cost international options closely when I was looking for a doctoral program for myself, and I'm not sure you're going to find one that meets all of your criteria.
You say that $10000 is out of your price range, so I think that eliminates Hong Kong. The open university in Thailand coordinates their doctoral programs with an Australian university, and I think the decent fee rate only applies to Thai citizens. Universities in India and South Africa might work better for you. You mentioned rankings, the ones that make the list of the world's top 500 are in South Africa, they're the Universities of Cape Town Witwatersrand, Pretoria, and KwaZulu-Natal. The University of South Africa has been a good solution for many, but it also has a reputation for formidable bureaucracy. To me, any of the universities there that are members of the Association of Commonwealth Universities would be fine, so you may want to start with a list of all their universities, which you can find here.
India's Indira Gandhi National Open University was on my short list because it actively encourages international doctoral students to apply. They've developed an informative prospectus just for people like you that you can find here.
You may also be interested in the University of Malaysia. I ended up finding an ideal American program, but if that hadn't happened I would have looked into this one more closely.
With this sort of doctoral study, typically it's best to decide ahead of time what you want the focus of your research to be, then to find a professor who shares that research interest. In that way, often which school you choose is secondary to finding the right professor to be your supervisor -- wherever that person is, you will be. Do you have a sense of what you want to research?
Also, these programs aren't online, as such. They just consist entirely of research you conduct that is supervised by their faculty. You want to find faculty members who don't mind supervising distant students by email or on the phone. Some will be willing to do this, others will not.
The thing is, you can find probably find something inexpensive that you can do as an external student, but it will be very challenging for you to finish in just two years. That's not very long.
Also, out of curiosity, are you not considering universities in Europe? If not, why not?
-=Steve=-
B.S., Info Sys, Charter Oak State College
M.A., Educational Tech Leadership, George Washington University
Doctor of Health Education, A.T. Still University, in progress