In this era of news related media turned National Enquirer and open kimonos so to speak, I won't ask how the 69 dollar amount was arrived at.
However, I would recommend you exclude tires/tubes from the total, as not every participant will have a supply of road worthy and safe used rubber.
With less than 2 months after the holidays to participate in this contest, and a major "to the studs" remodeling of my kitchen and bath, along with whole house new wiring, new plumbing, and new trim, I doubt I can find the time.
GOOD LUCK TO THE COMPETITORS!