I've found a couple places, ebay stores, that have Shadows boxes and some starters, but not much. Unfortunately I particularly want to expand my Crusade cards. Too many rares from that set that I really want, like Nova Dreadnoughts and General Ivanova. The big downside to Crusade is that it feels a bit cheesy if you build a deck based around some of the things introduced in Crusade, but don't give the other decks similar access. (I had a friend with a Well of Forever deck that basically could have been played solo, since at the time none of us had Crusade cards, therefore none of us had characters or fleets that could participate in the conflict.)
I still have 11 decks of my own, and two of my friend's in working order, along with a couple large flat card boxes full of cards. For anyone who cares:
Human (Bester): No One Can Stop Us -> Support of the Mighty
Human (4 Card Sheridan): Military
Human (Sinclair): Diplomacy
Narn (G'Kar): Military (Establish Base)
Narn (G'Kar): Diplomacy
Minbari (Transforming Delenn): Vorlon
Minbari (Neroon): Military, Full Mobilization
Centauri (Londo): Shadow/Intrigue
Centauri (Londo): Nanotech Plague
Centauri (Refa): Nightwatch diplomacy
Non-Aligned (Lemm Uh'Ekim, Vlur/Nhar): The Secret Masters
My favorite is easily the non-aligned deck. Who doesn't like taking over everyone else's characters?