Make sure to document all the pricing you get from contractors and suppliers so you can create a price list for all the basic items.

Same suppliers, same service for the meat cutting tools, same book keeper, same clientele etc. before that it was a welding business.

Start asking "Who is your fish supplier, can I get it at the rates you do, what's his name let me ask him myself so I can decide if I like his terms or maybe I can negotiate something that is more inline with my business"?

Another way the additional cost is sometimes mitigated is that contractors and suppliers are paid more reliably and therefore the process sometimes goes smoother and there are perhaps less change orders or delays - both of which are costly.  

Casinos are already not paying their suppliers for 120 days.

Maybe your tenant can go to his lender first or even his suppliers and ask for 60 day terms.

Also purchase cabinets with a local cabinet supplier along with appliances.

I am a little concerned with material suppliers being able to deliver to the property and how long will the rehab take now. 

When i was in the Timber business ( log supplier in the northwest) this was a key indicator to log prices.

I have been a member of a our local builders association for years but flipping doesn't work like a builder who sends a blueprint to their supplier and they send the materials to the job and install.