 Am I crazy?
timwiseman: Definitely an interesting thought.  I do have a few thoughts you may wish to consider:
1. Consider fewer case studies with more depth.  15-20 will involve a lot of contacts, possibly a lot of travel which will eat into the small savings, and limit your depth.  On the other focusing on 6-10 but trying to get in some real time with them (several hours each at least) will let you get a lot more depth with less travel.2. You may wish to carefully define entrepreneur.  By itself it means everything from small business owner, franchise owner, founder of a traditional, capital intensive company (like Intel for instance), founders of web/softare startups, and people who make things in their garage to sell.  I have not studied it formally, but I suspect this attract very different people.  Unless you specifically want to do a longitudinal study to compare between groups, I would pick one.  I presume you are talking about web/software founders, but this should be explicit (or explicitly rejected if I am wrong).3.  Remember you can publish this in numerous formats in short succession.  There is nothing wrong with starting with a series of blog posts as a near 'stream of consciousness' on the journey, and then follow up with a book that summarizes, refines, and adds more traditional research/statistics to go along with the case studies you generated.4. Related to 3, don't ignore physical books as a method of publication.  While it is starting to change, there is still a strong bias in many circles giving books more respectability than other forms of publications.  Also, they are more easily monetized than most other forms.5. If you come to Las Vegas I know one software founder and one small business (retail) owner personally I can introduce you to.