To recap, the your requirements are inexpensive and reliable to get you through college correct?
Here's some advice from a person that went to college, graduated and worked, and is now back in college living off of loans. In that meantime I've owned multiple vehicles, including new and used, bought in cash, loaned, and leased....and now being that I am 100% dependent on student loans, I know exactly the type of car you are needing.
I bought a used 1994 Honda Civic for about $4500 with 140k miles to drive my broke loan-surviving behind. Only thing I've had to do with it so far is change oil, put new tires on when I got it, got an alignment, changed an oxygen sensor, and replaced a belt. I do my own maintenance and all labor with the exception of installing tires and alignment. I also get 33-35 mpg on regular unleaded driving mixed city and highway.
The Civic is the most economical car that I have owned and it is INCREDIBLY easy to work on. The gas mileage is wonderful. And the motor out of my car is actually out of an Acura Integra (part of the reason it cost 4500 instead of 2500), but its a manual and I know how to properly drive to get the most gas mileage out of it. I expect this car to last me a LONG time and I spend minimal money on it for upkeep. Its an old car but these things are built well and built for the long haul. Additionally, any parts you will need to buy for it are relatively inexpensive and if you are mechanically inclined, easy to work on. Otherwise, just about any mechanic can service this vehicle. Many Honda motors expire well after 250k miles.
Used Civics from the mid 90's are always on sale. Many are well maintained, some are not. Try asking a mechanic to help you inspect. And many dealerships will do a "pre-purchase inspection" for like $75. You will have to buy these on the secondary market from Autotrader, newspaper classifieds, word of mouth, Craigslist, etc., but if the buyer is legit he will let you take the car to get inspected and if it comes back with no problems, it will be a good purchase.
Pros: Low initial cost. Low total cost of ownership. One of the most fuel efficient vehicles ever made. Low insurance cost. Easy to maintain. Very reliable.
Cons: It is an economy car, not a luxury car, so many amenities are not present. It is not the most aesthetically pleasing vehicle.
Hope that helps.