Regarding GPA conversion:
WES Grade Conversion Guide
And do you have any idea about your class rank or the reputation of your school? The best indicator of your chances for admission may be the sucesses and failures of similarly-ranked seniors at your school who have recently received their acceptances and rejections from CS grad schools in the US.
Right now, given your relatively low quantitative GRE score, I would suggest safer schools like UT Dallas and USC. (However, you may have a problem getting into USC with your quantitative GRE score.) Since you are concerned about costs, you may want to consider schools in Texas since Texas schools have lower out-of-state (international student) tuition while having lower costs of living. With your current profile, you would not be a good candidate for TAMU, but there are a number of schools in Texas with good faculty like UT Dallas, UTSA (University of Texas in San Antonio) and UT Arlington that are pretty easy to get into since they are unranked in USNews.
If you are interested in increasing your chances for admission to a better school, I would suggest something like taking the GRECS exam, doing an internship, and/or submitting a short 2-page poster paper to an international conference.
Regarding aid, it's tough for MS applicants but many do get a TA/RA/GA position after the first semester or so. At schools like UT Dallas, however, there are so many international students that getting a TA/RA/GA position seems very difficult for an MS student even after several semesters. UF offers a partial tuition waiver (usually about 40% or so) to a number of incoming students. However, your GRE score is too low for UF, so you would need to retake it and would probably also need to improve other aspects of your profile.