The BP calculator does not know unique location dynamics, supply and demand, redevelopment, gentrification, demographic patterns, job and population growth or lack of, schools, crime...you get the picture.

., go to the local supply shop (not the big box places, but the places where the pros buy supplies). 

However, the lien dissolves unless the party claiming the lien files a certificate of lien with the registry of deeds of the county in which the property sits within 90 days of the last supply of labor or materials."

Turning the water supply off and draining the lines reduces the risk even more.

However; there's no guarantee of what the market in the future will do, as every area is different and it depends on supply and demand at the time. 

I went to home depot got day laborers ... bleach and other cleaning supplies all done for a few hundred.

The supply lines get blown out , hot water heater gets drained .  

And employment reference should be similar - any phone number the applicant supplies might be a friend who was asked to pose as the reference.Why?

https://www.har.com/content/newsroom/Highlights: Single-family home sales rose 5.3 percent year-over-year, with 5,260 units sold;Days on Market (DOM) for single-family homes decreased slightly from 67 days in February 2017 to 65 days this February;Total property sales increased 3.1 percent with 6,375 units sold;Total dollar volume climbed 4.5 percent to $1.7 billion;The single-family home median price rose 1.4 percent to $226,200, which represents a February high;The single-family home average price edged up 0.4 percent to a February high of $281,945;Single-family homes months of inventory shrank year-over-year from a 3.4-months supply to 3.2 months;Townhome/condominium sales fell 5.1 percent, with the average price up 2.0 percent to $210,887 and the median price up 4.6 percent to $170,000;Leases of single-family homes fell 11.5 percent with the average rent up 4.1 percent to $1,720;Volume of townhome/condominium leases dropped 11.5 percent with average rent up 2.2 percent to $1,515.

He is a pretty seasoned and knowledgeable economist.He was chief economist at bear steamedYes people will not like him because of his belief in supply side economics.But he is more than just a tv personality, he does have significant experience