If I replaced the decking with OSB it’d be 11-12K with lumber prices.   

(A poor one will let you mess up the logistics and will be willing to suffer the consequences because he's desperate and hungry for work)(Do not confuse toilets, tubs, and faucets with things like lumber, fasteners, sheetrock, mud, deck boards, decking, or the hundreds and hundreds of other materials that go into a renovation.

I bought the cheapest stuff aval from lumber liquidators and it seems to be ok.

If you are in an area where it would be easy (fast) for the hard money lender to unload the property of you fail to pay that too will help your rate negotiations. 

building cost for single story 2 beds, 1bath ,2 or 1 car garage unit  example our area ( between $100-$125 sqft /current lumber prices ) cost of building (not include land) of 4 plex, rent is about average of  $1 per sqft/M Any feedback is much appreciated 

If it were mine, when it's time for a new roof, I would look into having ALL of the bad boards removed and replaced by ones taken from only one side of the roof, to leave a big hole of missing boards on one side only, and the other side make it builder-new.Because the old lumber is larger than the new lumber (unless it is new lumber sized or could be shimmed up to surrounding height.I would then plywood the side I took the lumber from completely, so as to have one part plywood and one part boards.That MIGHT save money vs a complete tear off.Why throw away the good boards.Also I would assume the rest of the house might have some bad lumber in it.

The most expensive thing right now from pre-pandemic is lumber.

The shortage of lumber and building materials is causing new development prices to increase which directly increases the value of existing multi-family. 

I built a house in 2017 and looked back at what I paid for a few components. Here is the actual amount I paid vs. the same thing today. 

I am always looking at other interesting investment opportunities.My father has a teak and lumber business in Tanzania and he is now expanding that into Uganda and Congo.I am discussing with someone about starting a business in Ghana, so hopefully that opportunity will come through.