Somethings it even more expensive than buying a new construction in a class A neighborhood.The turnkey investments are not always the best option for every investor especially if you are just getting started and low on cash or you don't have reserve/emergency funds to deal with issues like maintenance and vacancies.  

Here is a list of Construction, Rehabbing & Generic PM softwares that may be a good solution:Construction, Remodeling & House Flipping Specific PM Softwares BuilderTrend/Co-Construct - Home building project management software specifically built for custom home builders.

This is all changing very soon with the construction of the Foulger Pratt's new "WestEnd Alexandria" Landmark mall redevelopment, a new 4 million square foot mixed-use redevelopment, including a new 1.1 million square foot Inova medical center already starting, with completion set for 2028.The development notably won the Red Clay Development of the Year award.On top of the +2,000 healthcare worker jobs the development will immediately bring to the area upon completion, the 120,000 square feet of office space will also bring a large number of jobs to the west end of Alexandria.

We have booked guests while finishing up the construction phase. 

Make sure to get plenty of toy construction tools so they can help you rehab properties when they get older!

However, if you have the time and prefer to source properties on your own, I would highly recommend the following strategies:Connect with probate attorneysVisit property auctions: These happen monthly and, surprisingly, aren’t saturated with investors.Cold callingTarget LLC owned properties: Over the years we have seen an influx of companies purchasing SF for rentals/long-term holds and they failed to account for property taxes and an increase in new construction coming to the market.

Does anyone have experience working with "Nailed It" construction company?

Quote from @Dina Schmid: You can sell anything you want, but that doesn't mean it will qualify for a home loan or be accepted by a building inspector. 

I'm seeking opinions and examples of per-square-foot costs for constructing new multi-family developments in NYC. 

I think about my market (Cincinnati) and the only reason you don't see new quads is cost to construct is generally too much to make sense.