I am wondering what kind of costs to calculate in, what amenities to offer, and what the average vacancies are for this kind of rental. 

@Jack LeeTo improve deal analysis skills, use BiggerPockets Calculators, YouTube channels, podcasts, books, online communities, Excel spreadsheets, and local networking events.

Your cash flow calculation is missing vacancy, maintenance costs, and capital expenses.

In most cases, parental income is calculated in its entirety.

I'm unsure of how it was calculated or if it may have been an assignment fee that was misinterpreted on their part but they were the seller's agent. 

Also to note my brother is a journeyman plumber who is willing to help on any plumbing repairs should they come up.Financial ConsiderationsThe numbers look good using the BiggerPockets calculator, but I have concerns about our ability to pull off a BRRRR strategy due to cash reserves and DTI constraints.

Add at least $3k per year to any repair and maintenance expense you’ve assumed in your expenses calculation 6.

Only on rare occasions, when I had exceptionally clear thinking and well educated person (which, I will emphasize, was rare in wholesale or car buying business), I would go into details, break down the numbers, show my spreadsheets, sources of information, calculation and justification for the price I offered.

I use the 1% rule as only a pencil calculation. 

I am a spreadsheet junkie, so of course, I also built my own custom underwriting calculator!