Can a Computer Science Post Baccalaureate Student get Graduate Assistantships? Recently, I have been going around university websites to find a good post baccalaureate computer science programs. Most of them cost around $45k for living and tuition. Well, I was wondering is there any chance that post baccalaureate Students get Graduate Assistantships? Or Are they eligible to do any other on-campus Jobs?
Depends on your profile. If you are expert in a specific track and the faculty realizes that you might actually be able to assist the students, you would easily get a GA/TA/RA. An alternative to that can be tutoring, I've tutored all through my grad school. It actually pays almost all of your living expenses.

Of course any and all students are eligible to work on-campus for 20 hours per week during the school session and 40 hours when the school is not in session. This applies to international students too, if they are on F1 visa.