Going through the same houses in the same neighborhoods.

Single family home in need of some TLC for sale in western PA for $39,900.Median house price in the neighborhood $75-80kAverage rent for a similar property in that zip code $850-$900I would be putting down 20%, 5% interest, 30 years.Allocating $15k for rehabTotal cash needed $24,177Rent: $900/moVacancy: 5% ($45)Taxes: $238/moHome Insurance: $38/moMaintenance: 8% ($72)Capital Expenditures: 8% ($72)Utilities/Landscaping paid by tenant. 

As long as you do your due diligence on the neighborhood you finally decide to invest in you shall do fine.

If you want to challenge the appraisal you will need a comparable sale of a similar property in your neighborhood. 

The renal rate is what I'm the most uncertain about. 3 bedrooms are going for between $1,100 & $1,300   there are not a ton of 4 bedrooms in this neighborhood that I have seen the asking rent so the $1,500 is based on the more general area.

The agent value comes in analyzing the value, neighborhood trend/knowledge, how to read/research the seller as to motivation, protective and trap clauses in the wording of the contract, which lenders actually perform, which title companies to avoid, which inspectors to use/avoid, how to negotiate when problems occur prior to closing, etc, etc.....all of which You you are not experienced/competent in.So, You decide.

It's much easier to do this kind of homework when buying an LTR where you know that pretty much every 3-BR home in a certain neighborhood will rent for around $1100/mon.

What are the best Class C/B- neighborhoods to BRRRR. 

If others are investing in the neighborhoods you've honed in on, talk to them.When I first started, having an idea of where I may invest, and questions about certain topics are areas is a much better convo to have with an experienced investor than to just go up with the general "I'm new and looking to get started but don't know how." 

We are going out in the next couple of months to get a feel for the different neighborhoods...