Arms and Equipment Guide page 39 introduces basic rules for supply and demand.
Kanto's Lament from Enemies and Allies is a magic sailing ship that flies at over double (40.9 MPH vs. 20 MPH) the speed of an Eberron airship, is bigger on the inside than outside, provides high quality foodstuffs and Unseen Servants for crew/passangers, has some magic balista, armor and ability to Plane Shift once a week. Crafting rules are included. Costs a bit over double a normal airship, but holds five times the cargo (only double with Stormwrack) at double the speed and no need for mark of storms. I think this is the only unique crunch in the entire book aside from the notorious Wrathful Healing.