For laminate/engineered/vinyl install you can probably find $1/sqft labor plus materials. 

The part was $275 and they wanted another $250 to install it.

It's a very cost effective fix we did until we installed on-demand direct vent units.We also have direct wired CO/SMOKE detectors within 6 feet of the hot water tanks etc as per bldg inspector.http://www.woodlanddirect.com/Chimney/Chimney-Liners?

Second floor loft drywall complete, ceiling primed.Down stairs bath Plumbing finally finished (almost a week setback) new tub combo installed and walls mudded. 

The good meters will run you $380-ish.Have plumbing repairs in past included installing "Studor" vents or air-admittance valves in the venting ?

My consideration for this is to do this as a subject to with installing a tenant buyer in there.

Since the sink is integral to a salon and this overflow not something normally needed, I would say you as tenant would be responsible to install (and pay for).  

I have alot of experience in doing "retro fit" installs in houses being rehabbed and or flipped.

I suspect you will also have to get hard-wired and interconnected smoke detectors installed since you are in the process of re-wiring.

You could buy notes as well, but this requires access to substantial cash.The reason I say “control” is because it is possible to build CF without actually taking title to property; sandwich techniques such as option/lease option/installment purchase and then turn around and do the same or simply rent.