From one tattooed non-trad to another.....
I totally understand about the money consideration. I had to make a similar decision albeit several months ago now. As it has been mentioned previously on this thread, I turned down a number of, what many would consider, highly ranked and desirable medical programs to attend OHSU on a full scholarship. However, I have always thought very highly of OHSU, I'm excited to attend, and I don't feel like I'm settling by any means.
With your undergrad debt, that extra 100K or more could also mean a whole crap-ton (technical term) less interest over several years. Also, being 1 of 10 from a group of 165 is an honor as well. I certainly think you would make a great classmate and colleague, and I was personally looking forward to meeting you. However, being a physician is a difficult enough job as it is and I wouldn't think twice about accepting an offer to help relieve some future financial stress.
Don't feel bad about changing your mind either. You held onto that acceptance for a reason. In December, I thought there was nothing on heaven or earth that was going to keep me from choosing Emory. Even my visit to the holy land known as the Mayo Clinic didn't sway my decision. Financial assistance changes a lot of things and it's a real concern for most of us.
Good luck with the deliberation.