I am in the EXACT position you are in, only in NY instead of MD. I have considered having a room mate for the same reason you have, that it would be a lot cheaper, but for me, the other factors seem to outweigh the cost benefit for me.
I know myself, and having not lived with a room mate for awhile, I think it would be hard to go back to that, especially someone I don't know. I will have enough stress with starting law school, trying to get good grades to keep my scholarship and trying to maintain my relationship with my boyfriend, adding another wildcard into the equation may be more of a stress in the long run than I may want or need, depending on the room mate of course, and considering we are 4 months from starting school, I'm not sure how well you would get to know anyone you would find to live with at this point. And they might be OK with your boyfriend coming over a lot at first, but come finals time things may change (that is from first hand experience).
On the other side though, there are TONS of people who find roommates and are able to make it work, just depends on the type of person you are.
Hope that helped...