The low cap neighborhoods - you know those by the beaches- are the most desireable and low cap neighborhoods. 

A beach house with a bungalow in the back, in a tight market, in a highly desirable area...

The ethical wholesaler makes sure that they can close even if their desired buyer pulls out. 

However, I've also read that if the tenants live with clutter, decorate the house in a less than comely manner or make it seem in any way less desirable, it can negatively impact the appraisal.

its all about price point for most.its hard to do anything with 50k in a market were the median price is way north of 500k.. so mid west is an affordable option for those that for whatever there desires are want to be landlords or real investors.. simple as that in my mind.

You can find deals in less desirable areas like the poster above me.

nksYour comp method leaves a little to be desired.

In terms of units, last I heard from the PM's-- they say that they're in dire need of 1 bedroom/1 bath units--that's currently the most desirable, and least available

The downside is that there would be more work and a single family home will cost more, so for the same $ you are very likely to have to purchase in less desirable area/ less appreciation... but I would opt for more initial $ with more control.Their ability to control fees (I felt I was paying for a large management structure) did not appeal to me, but you would certainly be better hearing from someone with direct experience.

Per my realtor of the three, fuel oil is considered the least desirable.