Here is what I would look for in this order
1. the bike fits
2. the bike fits my budget
3. the bike has a triple on the front (hills)
4. I won't freak out when it gets stolen
5. I can easily ride the bike with one hand full of books and a back pack and a coffee (that means no to a road bike)

I would think that garage sale would be my first choice or ebay.

GG