I am firm believer that it all comes down to supply and demand.

Normally, the company negotiates for the tenant based on insurance information and variables submitted directly to them.  

If the well services 15 homes or 25 people then it will be considered a public water supply and need to conform to EPA regulations which are terribly restrictive.  

Depends on the market, and how many skilled workers there are, law of supply and demand and all that.

We always supply w/d with all of our homes.

I wasn't sure if a regular nail gun was used or if it was something special.I talked to a guy at the builder supply store today, and he confirmed a regular coil nailer is used with "stiff stock" 1 1/2" nails.  

@Aleksey Vinogradov - at least in my area, ready-mix companies usually only supply the product... you'll still need a contractor to place the material, unless you're doing it yourself.

I realize there are many variables such as region, weather, previous rehabs, and quality of construction methods originally used on any specific house, but I'm just looking for generalizations and things to watch out for.

They seem to have an unlimited time supply and pickyness about seemingly random things. 

I believe it affects supply and demand mostly?