There's absolutely nothing wrong with deciding to invest from the leftovers you have from your students upkeep. What really matters is planning with what you have. Some people have the opportunity and privilege to come from a better family where parents either hand you a credit card or place you on monthly stipends for sustenance. It won't be out of place to save a percentage for any other purpose as well as bitcoin accumulation. Going into bitcoin accumulation does not mean that you must always maintain your accumulation at a set interval . As someone under parental care, you have very little or no emergency funds, hence your parents do that all.
Unless a student that have good financial backup from their parents or probably if they also earn an income while still schooling. Investing in bitcoin requires discipline and someone who is still studying needs money for tuition fees and other fees that will help propagate the learning process so if they enter into investing in bitcoin without a good financial support system, they can sell their bitcoins earlier than they targeted. There are some parents that are strict regardless of being wealthy such that they allocate a fixed amount that can propel their children within a specified period of time such that they know that amount can sustain them till when the time for their next allowance arrives, so if a student in that kind of situation used up their left over amount to invest in bitcoin and peradventure they need money to attend to a need, it will become difficult for them to manage themselves till the next allowance shows up thereby putting themselves in unplanned pressure.
What am trying to say is that for anyone who is studying and under parental financial guidance, they can figure ways of earning while still studying so that it can help them while investing in bitcoin because they will now have enough money to invest with and still have some reserved funds with them.