Say a PhD student has a salary paid through a RA/TA or a fellowships but said student has no money for conferences, lab experiments, or to visit another lab for a few months to develop an important part of the thesis.
Should the student pay for these expenses out of his personal money? Is this acceptable, or should the student cut down on the project or change project to accommodate with the budget restrictions?
EDIT: Think of students from small departments and from countries where research money is little to non existent