keep in mind, returning stuff to best buy now requires your driver's license, which is swiped and then stored in a national database that is shared by multiple stores to track consumer returns. hit a threshold of returns and all participating stores in the database will deny all future returns for you.
that said, combine this w/ $20 amex = $45 total return on $250 giftcard purchase -- end up with $275 in "kindle" giftcards (redeem BB giftcard / $25 offer) for $235 out of pocket (plus rewards on the credit card and a $5 reward zone) -- not too bad.
ends up with an effective discount of 15% at amazon not counting the reward zone / credit card points.
how can you buy kindle giftcard?