I haven't read all the posts here so I apologize if some of this is redundant.
I graduated from Columbia's postbac program a few years back. It has it's pluses and minuses. But if you stick it out at their program, and do well, you will get into medical school. It's pretty much that simple. Some facts about the program....
First off, it is no cakewalk. Just because you get in does not mean you will finish. They're attrition rate is 40%. In order to emphasize this I'll tell you my roommate had recently obtained his doctorate from MIT in nuclear engineering and he chose to withdraw from the program because he "didn't want to deal with all the stress." Of course, he was getting As at Columbia, but he couldn't handle the stress level and workload that came with them.
Tuition when I went there was about $2K a class. Manhattan is expensive, but Morningside Heights (where CU is located) is less expensive than lower Manhattan. I relocated from Texas so they gave me a university housing contact at the tune of $500/month. It's hard to beat that anywhere in NYC.
It is easy to get into Columbia's program. They'll take anyone with a GPA of 3.0 or higher from their undergrad years. Like I said before though, it is much harder to stay there than get in.
The literature when I went there said that students that successfully complete their program obtain admission 89% percent of the time. That is far and away better than most other programs out there. Everybody I know that finished got into some medical school. The ones that didn't I heard, I'm sorry to say, were mostly those applicants that above forty years of age. The program got me into three (two MD and one DO) with a 3.3 Postbacc GPA and 32 MCAT. I'm happy with the medical school I now attend, and see Columbia as integral in my success, so perhaps I might be a little biased.
If you really want to get into medical school and are willing to do whatever it takes, and you have a GPA above 3.0, I would say go to Columbia. If you work hard and make the necessary sacrifices, you will get into medical school.
To research it more, go to
www.columbia.edu and follow the links to the School of General Studies.
Good luck.