If I ever found another startup, I'll do it somewhere with significantly lower rents but proximity to a startup hub. For example, the Santa Rosa area fits the bill in SF, and there are areas of New York that are significantly outside of Manhattan or Williamsburg. It's just not worth the runway hit, and those locations force you to try for a certain kind of funding that might not actually fit the startup (or its stage) well. Cities like SF have enormous value to a startup but not so much that you have to be in them day in, day out. There was a time that this was the optimal thing to do, but I think it's passed.