I am also building a group of investors to syndicate with, so more cash available soon as well.why?

ThanksIt would be very difficult to accomplish this. 

You could have 10 of these, and they get progressively difficult.  

If not, it’s likely going to be difficult.

On the flip side, if you've got a bunch of Section 8 tenants living in a building that's in a neighborhood where a lot of the tenant base has good jobs, high credit scores, and are generally reliable people, you've got the most risky tenants in that tenant base and that ain't what ya want.

Agree it is difficult to assess costs when they vary so much by location.Keep in mind that some turnovers are sickenly expensive, and that is just the nature of the business. 

It was also difficult to assess the heating situation after repairs since tenant refused to provide key to access unit for repairs and/emergencies, citing “privacy and safety” concerns.

Finding a good account and bookkeeper wasn't difficult and using online registered agents was way more cost effective.

Let's assume that the neighborhood is a C class and the median income of the city is greater than 3X of the market rent.Here are some of the considerations I've come up with so far:- Units are in need of renovation and capex is too high or not available- Unit quality is not the same as market - Seller is worried about losing tenants due to increase- Vacancy rates are high or filling units have been difficult- Rent increase would take multiple increases over multiple lease periods to get to market rate if seller is trying to retain the same tenant- Seller inherited property and just want to liquidate- Seller needs to liquidate quickly (financial burden, sickness, quick exit from land-lording)It seems like I might be missing a warning sign about a deal if they are selling with current rents that are under market; but again, this seems to be most of the properties I've underwritten.And in the same vein, what should I be worried about when purchasing a deal with under market rent with the intention of raising them after purchase. 

Then you'll need to build a team of contractors to handle renovations and to help with things such as property inspections.