Monthly cashflow does not account for vacancy, repair, cap ex.

Vacancy, capital expenses, and repairs would be the big 3.

I'm preparing to repair/replace HVAC and plumbing.

If you do that, you must put a cap on taxes, insurance, and repairs......and that will never happen. 

As you may know, a good portion of your monthly rent will not go in your pocket, it will go to the constant maintenance, upkeep, repairs, taxes and the like.Fourth, ask yourself... if you have a vacancy, the economy goes in the tank, you have huge unexpected repairs, etc....will your tenants chip in to help you out?

Factor in ALL expenses like property taxes, insurance, repairs, maintenance, vacancy rates, and potential property management fees.2.

I think that there are lot of properties where the purchase and rehab costs will be less than 70% of the after repaired value. 

I really never repair appliances.

We have an 11-unit apartment building (five 1br/1ba, six 2br/1ba) and want to do a cosmetic rehab (new kitchen, bathroom, paint, sanding, and staining hardwood floors, excluding repairs on MEPs).

There's certainly other aspects that you need to consider such as pricing, quality of photos & overall listing, is it clean/repairs are done, if there's tenants are they being decent to people during showings, are you requirements reasonable etc...