It is entirely possible to accumulate savings as a graduate student on a measly stipend… just be prepared for years of boredom, loneliness, and slovenliness.
For the record: I have managed to save $20k over the past 5 years of graduate school. Apparently this is a major accomplishment, who knew? I certainly didn’t. Was it worth it? The answer is unequivocally, NO!
Hedonism is always the superior choice.