If it were guaranteed that the price of bitcoin would stay the same as it is today, would you still buy it? My guess is, the answer is no. But if its value lies in being a currency, price stability is essential. And if your answer is no, how is it then not just a Ponzi scheme? In other words, everyone is buying it on the hope of someone paying more for it in the future, not to use it as a currency.
As a student if its price will stay the same and surely I will not gain profit from it then I would not buy it because I do not need it. Still, there is a lot of person that will buy bitcoin because of it anonymous and decentralized system that protect the profile of its users. I guess most of criminal in the underground market will buy bitcoin to be use in the transactions.