If I rent that property out I am basically switching to a different method of calculating value.

In Baltimore you can buy a house for under $10,000 and rent for $300-700, that's good cash flow, you may not want to invest in that area.Cash flow in my opinion is a function or your negotiating skills, your ability to use power prospecting methods and to create leads that make sense.

Any other method or strategy is subject to risk of audit.

Check your state laws regarding legal methods of notification.

While I'm sure that many methods are used, what are some of the typical ones? 

The comment was made that's one successful deal using their methods.

Let me give you my .02 on the pros and cons of each of the methods you laid out there.MLS-great source for deals, just like any other type of marketing you have to do it consistently to get results. 

However, the industry is moving away from this method due to high costs.

Different priorities mean different REI niches will be more or less applicable to your situation, and different REI niches require different methods of research and decision making, that's all.Thanks for the opportunity to clarify! 

Please contact me if you can help, or you know a licensed agent who can help.For more information on this method, check out this link:http://www.mris.com/mris-customers/subscribe-to-mris/join-personal-assistants-office-secretaries