For updates done where you cant recoup capital back through refi I like to see the cost recaptured through the resulting raised rent in under 10 yrs (or less if you plan to sell before then) -  otherwise the updates might not make financial sense on a buy/hold.  

Not glamorous at all but in my opinion are the best and highest returning assets in Miami for the last decade.We can get in an out of a flip in under 90 days with rehabs if any from 3-14 days with zero headaches and zero risk because they are always great cash flowing apartments to begin with.Now with Argentina’s currency inflation issue we are seeing the next wave of cash buyers that’s gobbling up our flips.

They fund new builds as well, https://www.fundthatflip.comHave been pretty easy to work with, and close loans in under two weeks at reasonable rates, around 8-9% 1-2 points. 

I found it on the MLS and went in under asking.

Reason is, the rental market is inundated with pricier rentals that exclude a very large part of the population that do not make a high W2 salary.

I'm want to be in the business of repositioning apartment buildings in less then a year and then sell it.So here my second question:What would be a quick and dirty way to estimate the ARV in under a minute (assuming you're using the maximum rent the market will bear AFTER rehabbing the units)???

If you’re inundated with good potential tenants willing and able to pay high rental rates, then that’s probably the way to go.  

Buy kwikset smart key locks you can change the key yourself or have someone do it in under a minute.  

Because of our location and how much space we have, and the fact that you can ship any where in the States in under 3 days, it has become a center for distribution centers - they are building them for miles around here. 

Based on what you describe a determined competitor could build it in under a month, except (perhaps) for your training content.