In your shoes, I'm not sure what I would do. I changed my name before I got my diploma, but I was still living as a woman; it's more socially acceptable for a woman to have a man's name than the other way around. And in the years afterward, I did have some interesting situations because of my name; if people don't read you as female, your experiences may be even more, um, interesting unless you choose a gender-neutral name. If you are consistently read as female (or if you don't care), then your case is obviously different.
Colleges tend to be very accommodating about name changes after you have graduated, but it's definitely better to take the leap beforehand if you can swing it.
If you are worried about money, see how much name changes cost in your area. You might be pleasantly surprised. In addition, if you are in the U.S., many states--perhaps all--offer fee waivers for low-income people. I assume that, as a student, you would have a good chance of qualifying. Look into your local court system's site and look over the name-change sections. If waivers aren't mentioned, do a search specifically for fee waivers because some sites don't make that information easy to find (or they put fee waivers into their own section, since waivers apply to many different legal situations, not just name changes).
Also, if your campus does not have an LGBT center, you might be able to get some support and advice at a community LGBT center.