If the car wasn't beaten on too bad by the previous owners and you keep up with the mechanicals it's really not an expensive car to maintain. I spent a few hundred dollars when I first got my 92 Supra on a full tune-up, replacing all the rubber coolants hoses, all the belts, etc and it's treated me pretty good ever since. Prep work like that goes a long way towards bringing the cost per year down, but you do have to front the money. It will save money in the long run, many times when something breaks it takes something else with it or requires purchase of something abnormal like a tow truck. The more mods you put on it and the harder you drive it the more things start to break or wear out prematurely, and of course it's a progressive slope. A few mods like intake exhaust and boost controller won't make a huge difference, but a large turbo will.
If you can do all the work yourself I'd say $100 annually bare minimum. Basic maintenance adds up. Tires, clutch, plugs, wires, fluids all wear out over time. The more you try to do it cheap, the worse the car will be. It's not a good car for broke college people IMO. It definitely won't be as cheap to maintain as your current vehicle, but it should be a lot more fun even stock. I probably spend 300-400 a year in maintenance (averaged out since I bought it), but I also do a lot of preemptive repairs and I'm running enough power to eat through tires every 15k miles. In the end it's well worth it for me, I can't see myself driving anything else.
