To calculate the price per unit in an apartment building with common areas, you'll first need to determine the total cost of the building, including the common areas.

These rules, which include a requirement that sellers set aside a portion of the purchase price for buyer-agent commissions, prohibitions on modifying the commission, and permission to filter listings by commission, all enable NAR, its co-defendants, and its members to maintain buyer-agent commissions at supra-competitive levels unrelated to brokers’ experience or the services provided, steer home buyers away from lower commission homes, and drive out discounters—among other harms."

@James Carlson @James Carlson was $630 including new faucet and installation. 

That includes the mortgage, the insurance, if there is any electricity the landlord is responsible for, if the landlord is responsible for any of the water and sewer, not all of those bills might be every month, some might be quarterly or twice a year like the insurance, and a small percentage set aside each month for vacancies, maintenance, and eventual capital repairs.

Bottom line up front – I’m not happy with the service and I likely wasted 5k.

So the purchase of the home included the empty lot.

Your calculation of $40,000 out of $160,000 would apply if the total investment included both the property cost and the materials/supplies, but in this case, it seems the property cost is separate.

Not only is the current owner asking for a 300% price increase over what they asked in 2019, but they have included in the new asking price the cost of the garish furnishings they want to sell with the home.  

This includes electricity, water, gas, and any other necessary utilities.3.

Market participants are waiting to see what inflation will portend for the month of March, including bond traders who are staying away from the 2 and 10 yr.