I agree completely that within most all large markets/cities, you can find a range of returns from single family homes that have high owner occupant demand and priced to where there is no cash flow as a rental and maybe hope for a break even and future appreciation/rent growth, or go to what may look good on paper (lower purchase prices in troubled areas) and deal with more possible rent collection issues, evictions/turn over, property damage. If you screen tenants and manage places well, definitely have seen people do fine working in more the C class rental space. There at least is always rental demand out there for more affordable options. Long way to say, I don't know if you can just focus on cash flow and pick a market that way without the whole picture of what you are investing in (neighborhood, condition, etc) and if you go with a cheap place in a troubled area, do a good job of managing the tenants/property.