(Another alternative would of course have been to exchange the internal SSD, but prices here even for used ones (and not those by OWC) are currently more than 150 euros, and exchanging it voids your warranty.)
Thanks for the update. With the storage sizes of the past MBAs as they are, I think this is a great topic.
Thanks for the update. Just a comment though... exchanging the flash storage in a MBA does not void your warranty (at least in the US). Even though Apple might like you to believe it voids your warranty, that is not the case. The Magnuson-Moss Warranty Act prevents companies from applying these "you can't replace anything" types of restrictions on warranties.