Michael, no problem. :) I could see that's where you were going, and I wanted to help you to make your point with some real numbers (it's the consultant in me). Besides, I can tell from your comments that you're either an investor (as am I) or you at least work with and understand them, and most investors I know--including all of my mentors--are pretty generous about sharing what they know (because they want to help others to learn how to buy properties the right way).
Debbie, I know for sure that you can buy some duplexes in the bay area (especially closer to some parts of Oakland) with the numbers I presented earlier, because I've seen (and ran the numbers for) some of those deals. However, it will probably be much easier for you to purchase a 4-plex that will yield similar numbers.
The key to buying a property right has less to do with buying it cheaply; rather, the key is to understand how the numbers work and what they mean--whether you use third-party software or write your own software as I do. The point is that your purchase price--even if you were to obtain a property for free (legally)--won't matter if the numbers don't work. Again, Michael is correct: "[there] are so many ways to look at the numbers. . . ."
Additionally, don't let the sticker price scare you. There are lots of ways to finance the purchase of an investment property: seller financing, conventional (commercial and residential) financing, private money, partnerships, etc. Each method has its pros and cons, and you could even use 2 or more of them together. The most difficult part of buying an investment property is finding and structuring the deal itself. if you put together the right kind of deal, then the money will come.