Literally never.
The poorer students when I was at uni (myself included) had to be noticeably much more frugal than our wealthy peers. It's frustrating and demotivating when you're working your arse off to compete, and your classmates have £thousands more to spend on leisure every term because their parents are picking up the tab for their accommodation and food.
The biggest difference between myself and the people I spent time with money wise was the more people went out and drank the "poorer" they were. There was a direct correlation between those that drank the most and those that had no money at the end of the term... Different experiences breed different results.