I'd personally rather not explain myself to someone on NS, of all places, but $50 is food for a week or two depending on how I spend it. Tuition is covered by loans and grants, but all the other shit is up in the air so I do what I have to. This is just one way of many that I make a few bucks so I can keep ramen in the cabinet and milk in the fridge. I'm sure you live with mommy and daddy or are part of the trust fund brigade so you don't quite get it. Or maybe you're not, but you sure as hell come off sounding like it, which speaks volumes to your personality and sense of self-worth and the worth of others.
Whatever, that's all I have to say on that - I've found over the years that arguing with kids such as yourself on this site in particular over things that they don't quite understand yet (like bills, rent, a $20k a year education) to be counter-productive and an overall negative experience.