Are there any online computer science course I can take for under $800?

[Ostronomos]

There are many options for online programs and there is no end to computer science courses. But a lot of them seem to be quite pricey. I was hoping someone could point me in a direction where I can major in computer science for under $800? Where I can actually earn a credential.

[stryder]

Are you after a qualification under the assumption that it will open doors to employment or just after the training itself?

In most cases Computer Science is Practionary (hands on), it requires evolving your understanding of the methods, principles, languages and applications which goes far beyond any singular qualification. 

When attempting to get a job, it might be fine to have a piece of paper to say you're qualified, but most bosses will be more interested in a portfolio of work you've previously done and what you can do right then and there without going online to work out how to code through reference material.

Sometimes part of the interview process might have them spring a simple programming task for you to write a solution in pseudocode to prove that you know what you are doing.  If you can do that you can actually prove to be of more use than someone that has a bit of paper saying they can do it.
(One such test was "program in pseudocode a solution for solving the 12 ball problem")

Get involved with or volunteer with some opensource projects (be active on Github etc), You could do some gig jobs for portfolio work.

If it's just that bit of paper you craze then there is a number of online "certificate" based programs, but what you'd need to look at is if the certifications can be exchange with modules on something higher. (Couldn't see anything mentioned on EdX/MitX)

And on a sie not just remember that if you do manage to get a diploma, don't smoke it. It doesn't lead to higher education.

[Zinjanthropos]

Quick google...

Best free online computer Science courses
MIT OpenCourseWare
Codecademy
Coursera
edX