The problem is raising money during the 3mo YC program is difficult and discouraged. YC founders have said they are discouraged from raising money until Demo Day or beyond, so they can focus on building stuff.
In very few cases will $80k vs. $150k make a difference before Demo Day, except for (IMO) hardware, certain other businesses with specific prepayments (maybe a licensing deal like "exclusive 12mo license for Kinect tech for pharmaceutical industry"), etc. But really hardware is the only obvious case.
I would actually go further and say it's not just difficult, I imagine it would be near fatal unless you were a well established company walking in. We found fundraising to be an incredibly soul sucking process and without at least a firm grip and a solid plan for what you're doing you wouldn't make it far.
While not nearly as bad as fundraising itself, I would also caution people not to underestimate how much work a successful kickstarter is. A lot of work is required, and is continued to be required long after it has finished.
In very few cases will $80k vs. $150k make a difference before Demo Day, except for (IMO) hardware, certain other businesses with specific prepayments (maybe a licensing deal like "exclusive 12mo license for Kinect tech for pharmaceutical industry"), etc. But really hardware is the only obvious case.