Look for similar square footage, close by sold last three months.

A larger multifamily build would generally be more cost efficient as you have less exterior footage and can combine MEP systems.

Is drone footage and pro pics enough?

I would do some research on square footage and road frontage needed for parceling off additional lots (STR the house, sell off or build on additional lots).

The other townhouses in the complex and area are over $650k for the same size and square footage.

Say flooring, go to your local Home Depot and find a flooring you would like to use then do the materials estimate like that (remember to add 10% to your square footage for pieces that will need to get cut).

But since you keep mentioning the issue with Boeing, I will note that the Youtube video I posted is not a media article, it consists of clips of the footage of the US Senate hearing, where US Senators asked questions and Boeing CEO "answered" them (I added quotation marks, because he had no answers for most of the questions, including why Boeing sent US Senate papers with gibberish all over them instead of the production documents that they were required to). 

I did not understand the importance of square footage.

Every county has different requirements, such as minimum square footage for rooms; maximum number of occupants, hallway sizes (If there will be residents in wheelchairs); and safety regulations which are usually different that owner-occupied homes (for example- Interior fire sprinkler systems).  2.

Sort the unit type comps by square footage descending for best results.If you’re inside of market by $100-200… immediately bump by $75-175 and see what bites you get.