That's usually because they offer good cash flow and they have good economic and demographic fundamentals like job growth, population growth, diverse economies etc.

Rental Rates Projected To Increase For Dallas Apartments DALLAS (Multi-Housing News) – The North Texas multifamily market continued to show healthy fundamentals last year and into first quarter 2019, according to Yardi Matrix.However, supply dampened rent growth, slowing it to 2.8 percent year over year through March, slightly below the U.S. average.More than 26,800 units were delivered in 2018 for a new cycle high, with an additional 44,700 apartments underway as of March.

If you invest for the long-term in DFW you will do well for yourself because all the fundamentals point to a very prosperous future for this market.

@Anthony AbdullahHey again Anthony, some of the others have posted useful responses but I feel there's a lack of grasp of the fundamentals on your part.  

I have been looking and poking around different states but have not really understood the fundamentals of choosing the right market for me to research on or look for.

Overall, this book fundamentally transformed the way I typically “do” real estate investment.

So of the items you mentioned that you don't understand are fundamental real estate business concepts.

-TRUST YOURSELF ONLYthe way BRRR is being touted in the book on BP  lacks a very fundamental aspect of BRRR I did as a HML over 2000 BRRR's for clients all over the country prior to the melt down of 08.. its how all turnkey worked at the time..Big difference though is I would not lend on the asset up front without an ARV appraisal before we even bought the place.. and as the lender I HAD the teams under my control.. since it was my money.. so the out of area investor had a TRUE team not a dream team of wholesaler realtor contractor  LOL.. which can be problematical as your discovering.. the only thing that goofed us up is when REFIs were no longer being done on rentals.. not saying it will happen again..But one really needs to know these things and be fully approved for the refi  including values before you buy the rehabber..had you done this ..

But if I had to choose one over the other I'd go with a quality property in a market with good fundamentals (jobs and population growth) even if cash flow on purchase was negligible over a building with high cash flow in a flat market.  

My confidence in pricing (especially, in a market like Boston) comes from the fact that it's being driven by market fundamentals.