I once traded a 19' Fishing boat that I took in trade for a down payment on a house and traded it for supplies.

You say to hook the garden hose to the "washer hookup on the house" but that's a water supply line, meaning water comes out of it.

I think all I did was procurement of supplies and installed 1 dishwasher. 

(Supply is also going up, but not fast enough to stop the rate of rental increase.)

However, this option also requires that they share their candy with other children who knock on the door and they will soon discover a rapidly diminishing supply of sugary sweets in their bucket.

If a contractor starts to do good work at a decent price eventually they likely will be flooded with business and up prices (supply and demand).Read J Scott's book on here from 123flip  

You will also have cleaning supplies, legal / accounting fees, and if in your area possibly AC maintenance.

Do you usually supply trash cans?

Still one of the lowest ranking cities for supply delivery.

Especially on the farm when I need to cut some metal away from a power supply which is 80% of the time.