Wow, I've never heard of anyone getting $25k! They told me the max they give is $20k and they offered me $18k ? Maybe it's different because I applied to the in-person program...but congratulations, $25k makes a huge difference! It basically brings the total degree cost to $60k. What other options (in terms of schools) are you considering? Personally, I would also ask Columbia how many strong policy placements are available in your area, and what some examples may be. I think ultimately, experiences do trump school name, but sometimes school name can also secure certain placements that might not otherwise be possible. However, even $60k is a lot of debut to take on- and since the max unsubsidized loan is capped at around $20k a year, this means there is a remaining $10k a year that you will have to either finance out of pocket, or take on higher-intrest grad plus loans for.
I do think you made the right decision to defer though-if you are having anxiety over the cost, it's definitely wise to take a step back and really evaluate what is right for you before proceeding. After all, you want to feel excited and fully at ease with the program you are starting!