Per R11, you need to find the fair market value of all non-KOP robot items.
Example: If you source some aluminum from a junkyard, the cost of an equivalent amount of
aluminum from McMaster-Carr would be an acceptable fair market value.
There are multiple ways to determine multiple fair-market values for one item. As long as the fair-market value you determine is less than $400 and your robot doesn't cost more than $4000 total, there's no need to find the best value.