Okay, a list of magic items/enhancements for the airship:
Dungeon Master's Guide:
-Bottle of Air (7 250gp)
-Decanter of Endless Water (9 000 gp)
Eberron Campaign Setting:
-Bound Earth Elemental (for landbound and underground travel)(CL15 + Greater Planar Binding)(1 200 gp)
-Bound Water Elemental (for aquatic travel)(CL15 + Greater Planar Binding)(1 200 gp)
-Bound Storm Elemental (to power Lightning Turbine)(CL15 + Greater Planar Binding)(1 200 gp)
-Wheel of Wind and Water (8 000gp)
Stormwrack:
Mundane:
-Ballista (500gp each)
-Bombard, Light (2 000gp each)
-Bombard, Great (8 000 gp each)
Magical:
-Captain's Lantern (12 000 gp)
-Living Figurehead - Dragon Head (40 000-56 000 gp)
-Planar Helm (65 520 gp)
-Sails of Displacement, Minor (reflavored to Elemental Mast of Displacement, Minor) (120 000 gp)
-Wind Pipe (7 000 gp)
Arms and Equipment Guide:
Mundane:
-Armor Plating, Adamantine (5 000 gp per section)
-Firing Castle (1 000 gp each)
-Masterwork Controls (4 800 gp)
-Ramming Prow (5 000 gp)
-Rotating Platform (500 gp each)
Magical:
-Captain's Table (72 000 gp)
-Charts of Certainty (47 520 gp)
-Earth Keel (150 000)
-Eldritch Exhaust (all 3 options) (2 160gp + 16 200gp + 23 760 gp)
-Lightning Turbine (90 000 gp)
-Nondimensional Trunk (30 000 gp)
-Planar Sails (reflavored to Planar Elemental Mast)(72 000 gp)
-Smuggler's Hold (90 000 gp)
-Veil of Obscurity (25 000gp)
Stronghold Builder's Guidebook:
-Ambassador's Chamber (10 500gp)
-Bed of Regeneration (91 000gp)
-Bed of Restoration (38 000gp)
-Bed of Wellness (all 3 options) (15 000gp + 15 000gp + 15 000gp)
-Bier of Inquisition, Greater (22 500gp)
-Bier of Resurrection (44 500gp)
-Cabinet of Stasis (66 000gp)
-Chamber of Comfort (7 500gp)
-Cloudgathering Orb (33 000gp)
-Everful Larder (15 000gp)
-Hole of Hiding (3 000gp)
-Inscriptions of Vacancy (22 500gp)
-Pantry of Preservation (3 000gp)
-Platform of Jaunting, Greater (76 500gp)
-Platform of Healing (30 000gp)
-Pool of Scrying, Greater (50 000gp)
-Room of Reading (750gp)
-Secure Chamber (60 000gp)
-Table of Safe Meals (1 500gp)
-Warding Bell (7 200gp)
-Well of Falling (1 500gp)
-Well of Flying (7 500gp)
-Zone of Elemental Immunity (10 000gp)
Man, that's a lot of stuff
EDIT: Okay, did the math...
-Airship: 92 000gp
With a Lyre of Building that becomes 73 600gp
-Magical Enhancements: 1 554 460 gp
The magical Enhancements can be crafted for 233 169gp, so we're at 306 669gp plus the cost for mundane enhancements.
-Mundane Enhancements: 9800 gp + 5000gp per section + 2000gp for each ballista we want to install + 3 500 gp for each light bombard we want to install + 9 500gp for each great bombard we want to install.
So, how many Landlord feats do we have in the party again?