I think other Hodgepodge has summarized the pro-Einstein position pretty well. I'm also going to AE next year, so I'm also biased in favor of the school, but here's my take.
If money is the issue, you should speak to the Financial Aid directors of each school
and see if you are eligable for any grants or scholarships which may reduce your costs. Then factor in the cost of living, commuting, maintaining a car etc. and other quality of life issues, such as the scedule of classes, nature of the student body, access to a gym and entertainment/recreation facilities. You might find that the difference is not as great as you might think.
I think the main issue is if you prefer a rural/suburban environment or access to an urban environment. The populations attending the affiliated hospitals of each school are quite different, and I susupect you might have more "hands-on" clinical opportunities at Einstein. Also, I've heard Stonybrook is a commuter school, without a strong sense of student community. Once again, this is something to factor in, since it may have a large impact on your happiness in the program.
Go visit the schools for a secondf time and go with your instinct, you really can't go wrong becuse both are very good schools.
Good luck!