.)- Licensed Builder (wanting to build my own MF units)  - Skilled laborer. 

If the copper makes you feel better then use it, plumbers in my area pipe their own houses in pex and only care for copper because they make more on material upcharge and labor to install.As a side note- acidic water breaks down copper, which ingesting can cause health issues, and can cause pinholes in copper piping.

I am not sure how you are intending to manage, but beware the local labor pool is not the greatest and I think you may have some issues finding either decent management or finding decent workers if you intend to self manage. 

Labor, materials, insurance, interest, local property taxes - yes.

Furthermore, on the cost and labor side, there has been no/limited easing.Personally, I do not think that the luxury traveler is in the market for April and May.

are you looking for them to bring funds or just labor ? 

Quote from @Joe S.: Quote from @Marcus Auerbach: You can absolutely run a property on zero percent vacancy!

Of course you can't do that indefinitely, and you still have to pay for the property itself and the labor, which you can't do with a card.

Quote from @Joe Davis: Quote from @Sarah Reece: After a lifetime in residential real estate I'm finally wising up and wanting to diversify a bit and start dipping my toes in the HM/PM space. 

Therefore to someone else that has to pay for labor, maybe the labor cost is a deal breaker for most.If you inspect the house and triple check your numbers down to the screws and nails, I do not see how you can go wrong.