Don't listen to rjakapeanut, he is clearly messed up in some manner. When he says running away is the move of a coward, we can see the corollary is that capitulating, allowing yourself to be manipulated, and letting her ream you for money for a child she deceived you about is the brave thing to do. Clearly nonsense, ignore his posts safe in the knowledge that you are missing nothing of any utility.
Metro has been giving good advice, but I would add to it. I think you should tell her, in an uncompromising way that under no circumstances will you help raise the kid, stay with her, or provide financial assistance. This removes a pile of incentives for her to have the child in the first place, and then, even if she does have it, to pursue you for money (which I imagine is a near certainty if she does decide to pop a sprog), make sure you tell her that you will leave the country if she attempts to take your hard earned money.
I would push heavily for an abortion at this stage, if you allow it to drag out and go for adoption, a big bond will already have formed, and she will be loathe to send it away, even if she agrees now, we have seen that she can be duplicitous. If pushing for abortion does not work, then your option is adoption, but right now, go for the abortion. You had a good idea with the cost/benefit, but make sure to emphasise that she will get nothing from you. Women are programmed to try and enlist the help of a partner in raising their children, by telling her (again, in an uncompromising way) that you will under no circumstances help her, it becomes a far less attractive option for her. Also, mentioning the drinking and smoking seems like a good idea, to take some of the shine off her potential motherhood aspirations.
If it came down to it, I would honestly leave the country and go somewhere fun, though you may be able to finish grad school, as they should not be able to take much money from you, safe in the bastion of education. Seriously consider this an option. Also, a paternity test goes without saying, I would also mention this to her, it shows you have a certain attitude and will not be bullied in line with her desires.
About all the moral shit you may cop; ultimate responsibility, lies with the party who has ultimate choice. No man can have a baby, men can only get women pregnant, there is a world of difference. In the western world, every child is the product of a woman not having an easily available, medically standard abortion. It is not right that you should be saddled with all the responsibility, but none of the choice in the matter.
Of course, at least you will have learnt your lesson about potential sperm bandits financially raping you and holding your emotions captive while they decide what to do with themselves.
Good luck buddy