[Kevin Sevcik]

I would think that cost equivalence is one of the factors. The rules make a large fuss about accounting for the fair market value of things no matter if they were donated, bought on eBay, fell off the back of a truck, etc. So I think buying and "equivalent" part somewhere that's cheaper and costing the lower price might not come off well. So you might need to use the price of the piece you're saying it's equivalent to.