Experience Vs. Payment

As of today I am facing quite the dilemma. I have interviewed at a few different places for the summer, and I hadn't heard back from anywhere until today. One of my interviews was at the Critical Care Department for Boston Children's Hospital, one of them was at Massachusetts Eye and Ear in Project Management, and the last (my favorite) was at Dana Farber with the Administrative Director. The first two are paid, but I haven't heard back from them yet. The last is unpaid as of now, but I just got an offer today! I am over the moon about it because it is my first choice, besides the unpaid part. I feel like I would gain the most experience at Dana Farber, as I would be shadowing the Administrative Director: Jenn Foley, and attending all of her importnat meetings. She is a fountain of knowledge, and someone whom I would love to have as a mentor. The only problem is that I, like most of us, need and want to get paid. I have to make the difficult decision of sacrificing what I believe would be a great experience in order to earn money, or take the unpaid internship and work my butt off seven days of the week. I would need to get a part time job for the weekends so that I can make ends meet. As of right now, I am leaning towards accepting the offer, as it is what I want and where I feel I fit in the best. I have a feeling this wont't be the last difficult decision I make regarding my career, I just hope I'm making the right choice!