China has cheaper labor, almost no EPA constraints, far cheaper electric power with their new Dam, etc.

For the first part of your question even if you were working with a realtor, I don't personally know many that have a true pulse on rehab costs and I wouldn't make any investment decisions based on their rehab cost projections.My suggestion would be to study how to evaluate the Big 6 rehab costs: roof, siding, windows, HVAC, electrical, and plumbing. 

Updates of heating, adding cooling, and electrical.

Covid related supply chain- We had a project where we needed a 300 amp electrical service. 

Costs like engineering and permitting can become disproportionately high for mid-size projects.Height and Density: Focus on areas where zoning allows for verticality and density.

Don't forget about paying to start electrical, gas, water and internet services.

SEO Search Engine Optimization manager, $1,500 per month.

Costs have escalated sharply, water up 25%, electric up 30% and natural gas up 33%, and at one property insurance went up 400%.

Electric, I have no idea…I don’t want to turn on the utilities, leave for the night and the place is either burned to the ground or flood.

We have also completed some exciting improvements including retyring a boiler for heat/cool ductless mini-splits and 9 units being electrically updates.