@Joshua A. Lenninger
The 50% rule is a good rule of thumb but may not fit your market. Its value is in ensuring that you consider all costs in analyzing your deal. And then determining realistically if your property will cash flow.
For me cash flow is important, I do want money in my bank account every month but I also want to be sure that this is the best option for investing my money. Could I do better in a simple savings account, or in mutual funds, a 401K or stocks and bonds?
The first thing I do is try to get as close to "1%" as I can before going into all the other calculations. I.e. I would probably pass up on the above mentioned property because $3,250 is less than 1% of $360,000. For me, anything less than 1% return on my investment (12% per year) means that if my expenses are roughly 50% of that, that at 6% per annum I have to determine if I could probably do better in mutual fund with less work and worry or if I think the property is a worthwhile use of my money as an investment.
What works for you may not work for someone else but for me, I want to know that I'm making the best use of the money I have available for investment and that I'm properly diversified between types of investments (property, mutual funds, stocks, bonds, etc.).
From what everyone says on BP, prices in CA are high and it isn't a market where the usual rules apply. Maybe if you think about it in terms of your overall investment strategy, you can decide if you want to go ahead without following all the rules.