Air conditioner is over 10 and for expense planning purposes we can expect to replace that within 5 years. 

I'm going to guess $4 a square foot, maybe more if the drywall skin peels off with the steaming and you must replace drywall then $6.

@Alex Ramirez, There is nothing statutorily against buying your replacement property from a related party. 

Own a SFR and the main sewer line collapses, you may pay $20K to get it replaced.

Under contract for $1,275,000, accounted for 1% closing costs, and threw in 50k for capex stuff (turnover and one of the roofs need to be replaced).

Now, I have to go to las Vegas to replace every floor molding in the house and I will have to hire an HVAC contractor to repair the AC and hire a welder to repair or rebuild an iron gate and fence.

For context, it's a $700-800k 2-unit MF, which I'm indifferent about in terms of going the owner-occupied vs pure investment route.

A roof replaced in 2015 is NOT old at all.

The act of refiancing pays off the existing loan as the loan/Note/lien is replaced by the new loan.I guess the point is you are short on cash to do your next deal, then yes I guess you'll have to refi. 

We remodeled the kitchen and bath, new lighting and hardware, refinished hardwoods, replaced the fuse box with a panel, replaced galvanized lines, painted throughout and partially finished the basement.