In general, does serving or retail bring in the most income?

I currently work full time and will need to find a part time nights/weekends jobs for the remainder of the time I’ll be in school (about 3 years). I need something with flexible hours so I can possibly work more while I’m on break or less while I’m in school—I’d also need it to be flexible so I can do a summer internship or two without having to quit and find another position. I also need soemthing that would bring me AT LEAST $185/week just to scrape by with my bills at around 25 hours per week. I have plenty of customer service and sales/retail type experience.

I’ve come to the devestating conclusion that I’m stuck between a job in retail or a job as a server at a restaurant. I know these things vary quite a bit, but in general, would I bring in more money in a guaranteed paycheck retail position or a tip-based server position? Which would be the better choice, do you think, for what I’m looking for in a job?

I start school in 2 weeks, so I’m starting my search now. I’m just not sure which way to go. Any advice/suggestions would be great!