From what I'm reading, you are in college going into the field of medicine which isn't cheap and you would like to reignite your interest into airsoft while under a tight budget. Well it sounds like you'll have to choose one or the other...or you can go to whatever games you can make it to and rent from other players. It would be your cheapest solution compared to buying a cheap $200max gun that'll probably break down on you after 2-3 games (maybe more if you can properly maintain that gun).
Get yourself Age Verified which will gain you access to the sites classifieds section, with some patients and lots of surfing around, you may find a decent airsoft gun that'll fit your budget. Quality comes at a price but sometimes you might just get lucky.
"Hey I'm the first one to say its a great country but its a straaaaange culture. This is a place where gun store owners are given a list of stolen credit cards but not a list of CRIMINALS and MANIACS. And now they're thinking of banning toy guns...AND THEY'RE GONNA KEEP THE F**KING REAL ONES!"
-George Carlin 1937 - 2008 (RIP buddy)