I’m not sure what you mean by 4 years of a dolarized salary. Students on students visas are extremely limited in how much they are allowed to work and I believe they are only allowed to work on campus. The amount you make will be enough for spending money.
After you graduate you must the country leave as your student visa expires when you are no longer a student. The exception is in certain stem majors, you can get permission to stay for a year to work at a job in your field. After that you have to leave unless you find an employer to sponsor you.