All costs must be retail cost of a new part, or so says the rules. So unless that eBay one is a new part from a supplier who just happens to use ebay is their sales medium (as opposed to a guy who had a spare one laying around and decided to sell it), I don't think it will work.
there is a link to a retail priced one, but the guy with the auction did have several for sale. Oh well I printed both, and bob can decide which one to use in the cost report.