There's no honor in being a poor college student anymore; Mark Zuckerberg messed that up for everybody. While you're sitting in microeconomics, be thinking macro. You're a Winner™ and a Winner™ doesn't need a job to get filthy rich.
You don't need superior skill to hustle pool, just a trustworthy partner and somebody willing to bet on a game of Cut Throat. Even two mediocre players can secretly team up to beat a good player for a nice split-able profit. Plus if you get caught, two people are harder to beat up than one.
If your dorm mates are more into board games, just buy a duplicate of their game of choice. You'll rarely lose The Settlers of Catan if you've got a pocket full of sheep you brought from home.
Pro move: You can win Scrabble by feeling the tiles in the bag and selecting the best one. You'll get better with practice OR by peeling off the first layer of skin on your index finger to increase the sensitivity. Then spend your winnings on a nice pair of gloves.
Most schools have a way to petition the student union for money to start a new club or sports team. Very few of those schools know that squash isn't a real intercollegiate sport.
Fill a team with friends who enjoy spending the school's money and can keep a secret. After a few months of fake scores in the student newspaper showing that the Squash Club is having a record-setting season, every student senator will happily vote for an extra $5,000 to send them to nationals in Las Vegas.
Pro move: Have a friend take bets against the hometown heroes in their big tournament match. It'll be easy to beat the point spread when you're the one making up the scores.
METHOD 3: Re-sell Food Service
The key to reselling dining hall food is finding pocketable foods with a high retail value. Granola costs a fortune at market price, but is free every morning. Line your pockets with ziploc bags and take a bowl or two out each day.
Desserts are also easy to pocket. If you don't have 100 cookies by the end of the week, you're just not trying.
Most importantly, don't forget that free toppings can be sold on their own. A $2 a la carte bagel can easily be piled with $10 of free cream cheese.
Pro move: I think it's about time the Squash Club had a bake sale in the quad: "Fresh" granola, cookies, and cream cheese can help pay for more "safety equipment."
Anybody can be poor. It's so easy, even poor people do it. But only a Winner™ gets rich between classes, and you look like a Winner™ to me.