grad school or work?

No matter what choice you end up with just make sure you're doing what you want. Make sure you're really interested in the course you're taking. Working ahead may cause some time for you to finish studies but it gives you experience you can put in your resume.

if your education expenses still much, should continue your education until graduate school. Thus you has maximal your time and make cost your education be effective. But, if you have exhausted your cost education or can't fulfill cost education post-graduate, previous should you must find a job or you still lecture, but while working

If you can do both, then go for it. If you have the money for schooling, then it would be fine to get a Master's degree, if you do not have the money, then get a job for the meantime. It is still different when you have a work experience because when you reach 35, it is very difficult to get a job by then. Grad school can wait unless you have to take that because you want to teach, then that is an exemption.