Originally Posted by Frenchie Flyer
I think you could show that on the "open" market these AAdvantage miles are sold for less. See the listing at EBay - item #2290639693. $499.99 for a 25,000 mile award. Not a big savings over what AA said it was worth, but nonetheless it shows that you could find a lower price for the same miles.
I'd be careful when relying on eBay. Some of the auctions are very skewed, either down (because the seller didn't use enough "search" terms in the heading, or misspelled them) or up (because two folks started bidding against each other without a good idea of what the item was worth).
For example, the Kellogg's AA Miles certificates sell all over the map. I've seen them go for $1 per 100 mile certificate (which would support a valuation of under 1 cent per mile, remembering that you still have to mail the certificates in to get the miles posted to your account) to (believe it or not)
over $25 for a 250 mile certificate (which would indicate a valuation of over 10 cents per mile). Most seem to go in the $1.80 to $2.50 per 100 miles range, but there can be some wide variations.