@Andrew UMphrey I might be late to the party but I agree with 18% if all the assumptions are correct. 

@Olivier Mader the assumption on tax reform seems premature, the bill hasn't been confirmed yet in its final state. 

The 3% bumps I would just discount with a 3% inflation assumption.

I am not one to make assumptions, but I would think this kind of law is applicable to landlords just about everywhere.

You have made some assumptions.

------------------------------------------------------------------------------------------------------------Assumptions:1) Purchase Price (PP): $150,000   (just over 70% ARV Rule)2) Financing: Interest-Only Loan - All Project Costs3) ARV: $300,0004) Rehab Cost: $65,0005) Fixed Costs: $52,284  (17.41% of ARV)Buying Costs: $5,951  -  (4.0% of PP, or 1.98% of ARV)Inspection: $400Settlement Charge: $900[Transfer/Recordation Tax: $3,675][Government Recording Charge: $60]Survey: $195Owner's Title Policy: $721Holding Costs: $11,148  -  (3.7% of ARV)Assuming 8-Month Hold PeriodLoan Payments: $6,532Property Taxes: $1,896Utilities: $1,600Insurance: $720Maintenance: $400Selling Costs: $35,185  -  (11.73% of ARV)6% Commissions: $18,000Home Warranty: $400Settlement Charge: $425[3% Seller Concession (standard for area): $9,000][Transfer/Recordation Tax: $7,200][Government Recording Charge: $60]Termite Report: $1006) Total Costs:  $117,2847) Profit:  $32,7168) ROI:  ~14%  (21% Annually)Not very attractive in my opinion

I’m looking to confirm/correct some of my assumptions.

He told me he gives this building a 10% vacancy assumption and was unaware of the shape of several of the units (vacancy more like 20%).Based on the loan history I can surmise that the owners have a lot of equity in the building after having owned it for 20-25 years, but they are not property managers in the least bit.

I know for a fact they don't want to deal with this property anymore, but they also have very unrealistic value assumptions.  

You failed to miss the entire point of the rant however you did provide the support for it with your ridicules assumption that there must be something wrong with me, otherwise why would I be ranting right?