These methods include: Detailed Engineering Cost ApproachDetailed Engineering Cost Estimate ApproachSurvey or Letter ApproachResidual Estimation ApproachSampling or Modeling ApproachExperience or “Rule of Thumb” ApproachIt’s important to understand the differences between the approaches including which one best fits your property and the reliability of each approach.DETAILED ENGINEERING COST APPROACHThis approach compiles the costs from construction and accounting reports to build a report.

You will learn the cost of maintenance/cap ex and how tenant quality plays a big role.  

Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

I've seen estimates that are off by 300% when all said and done (e.g. the original bid was $10k but the final cost was closer to $30k).

I'd highly recommend house hacking in your local market since you're in one of the highest cost of living areas in the US, especially if you're renting currently and planning on staying in the area for 5-10 years.It sounds sexy to go out and invest out of state for your first property.

@David F.As Russell mentioned co-ops are probably 1/2 the price of a condo and you would also have extensive costs to set up a co-op and typically it’s my understanding the builder funds the first 1-2 years of reserves.

Can try to reposition to Class B, but neighborhood may impede these efforts.Vacancy Est: Historically 10%, but 15-20% should be used to also cover tenant nonpayment, eviction costs & damages.Tenant Pool: majority will have FICO scores of 560-620 (approaching 22% probability of default), many blemishes, but should have no evictions in last 2 years.

For example do you have a great w2 and can you afford to cover costs of a major repair or 3 months of vacancy?

I'm curious as to what cosmetic rehab you have to do that costs $27K? 

The location all in,cost him X; he got an appraisal for the bank from CBRE national firmof XX and now the firm who called him mentioned paying XXX.