Screw working during the schoolyear unless you financially need to.
Some of my classmates (i'd say ~25%) are working scattered shifts or like a 5hr shift or two a week.
You think ah that doesn't seem bad, and it's not really but man when you're in class from 9-5 with 7 lectures and you have to leave the last lecture early cause you need to work from 5-10pm that must absolutely suck.
Let alone the fact supper is ruined and you have no time to catch up on all the lectures you did that day, all for 50 bucks or something? pfft.
And let's face it, not many pharmacy interns leave a retail shift thinking holy crap i'm so glad I got that shift in. I think a lot of people get hasseled into it by their employers, the company I worked for over the summer kept trying to persuade me to do some work with them during the schoolyear (Oh it'll help you apply what you learn), but they just want your signature on a contract when you graduate.
I'd much rather have that 5-10pm to get some food, relax, go to the gym and study for an hour or two. If you do my method, you'll end up saving money in the long run because you'll be at a less chance of developing disease.