There are a bunch of different figures associated with this decision, such as new interest rate, old interest rate, cash flow of new property etc, but I'm having a hard time getting my mind around how to analyze the decision mathematically.  

Are you asking about how to analyze the numbers for a deal?

I want to become really good at analyzing deals, and determine the markets I should focus on.Are there any resources aside from this forum (books, journals, news publications, podcasts) that you recommend I use to learn more?

Use your expertise in multifamily lending to analyze deals and start small with a manageable first property.

In the process of analyzing deals, I reached out a property manager for his fees.

Start by analyzing cash flow and market demand for each property to decide which one to rent out.

The vast majority of them will out themselves and you can decline to show the property. 

Finally, start small, analyze deals, and build a team to guide you as you gain experience.

The quick answer is "yes" AND there are deal analyzers on BP's site.

However, having an experienced real estate agent or investor in your network analyze comps adds an extra layer of confidence.If you’re focusing on specific markets and ever want to discuss analyzing deals or strategies, feel free to connect, Our firm would love to help you!