okay okay i hear you. sideloading MOBI files to your Kindle is a "big pain in the ass." believe me, i feel your pain, i too am no stranger to the heartbreak of Amazon.
sooo, PX Me: The Serial is coming directly to Amazon. soon, very very soon.
yesss, you will be able to purchase EACH VOLUME individually via your handy existing Amazon account. hurrah!
stay tuned via this blog or the spiffy new clean simple "books only" information page.
p.s. unfortunately, now that means Volume Four is slightly delayed. sigh