The problems with so many AWDs is the expense of the actual combat system, the major components of which, AEGIS and SPY, are fully imported and currently about US$250m each.
http://www.bga-aeroweb.com/Defense/Budget-Data/FY2015/DDG-51-NAVY-PROC-FY2015.pdf
On page seven of eight.
I picked AEGIS as many other systems would also be used on a non- AEGIS ship.
Talking of the cost of the AEGIS system, just saw this yesterday.
The US DSCA has just approved two (2): AEGIS Combat System (ACS), Underwater Weapon System (UWS), and Cooperative Engagement Capability (CEC) for Japan. Total cost of the package is estimated at US$1.5 Billion (or at the current exchange rate A$2.05 Billion):
Japan – DDG (guided missile destroyer) 7 and 8 AEGIS Combat System (ACS), Underwater Weapon System (UWS), and Cooperative Engagement Capability (CEC) | The Official Home of the Defense Security Cooperation Agency
The US$1.5B (A$2.05B) package price includes:
-Two (2) AEGIS Weapon Systems (AWS) MK 7
-One (1) J7 AWS Computer Program
-Two (2) ship sets Multi-Mission Signal Processor (MMSP)
-Two (2) ship sets AN/MK8 MOD4 AEGIS Common Display System (CDS)
-Two (2) ship sets AN/SPQ-15 Digital Video Distribution System and Common Processor System (CPS)
-Two (2) ship sets AWS Computing Infrastructure MK 1 MOD4
-Two (2) ship sets Operational Readiness Test System (ORTS) hosted in AWS computing infrastructure
-Two (2) MK 99 MOD 8 Fire Control Systems
-Two (2) ship sets AN/SPG-62A Radar, Ballistic Missile Defense (BMD) including Mission Planner blade server processors hosted in the CPS
-Two (2) Kill Assessment System/Weapon Data Recording Cabinets (KAS/WDRC)
-Two (2) ship sets Mode 5/S capable Identification Friend or Foe (IFF) System
-Two (2) ship sets MK 36 MOD 6 Decoy Launching System
-Two (2) ship sets AN/SQQ-89A (V) 15 Underwater Surveillance and Communication System
-Two (2) Global Positioning Satellite (GPS) Navigation systems with OE-553/U antenna
-Two (2) ship sets AN/SSN-6F (V) 4 Navigation Sensor System Interface (NAVSSI)
-Two (2) ship sets WSN-7(V) Inertial Navigation System (INS)
-Two (2) ship sets AN/URC-141(V) 3(C) Multifunctional Information Distribution System (MIDS) Radio Set
-Two (2) ship sets AN/UYQ-86(V) 6 Common Data Link Management System (CDLMS)
-Two (2) ship sets AN/SQQ-89A (v) 15J UWS
-Two (2) ship sets Gigabit Ethernet Data Multiplex System (GEDMS)
-Two (2) ship sets Maintenance Assist Modules (MAMs) cabinets for Fire Control and Combat Systems equipment
-Two (2) ship sets Multi-Function Towed Array (MFTA) and associated
OK-410(V)3/SQR handling equipment
-Two (2) ship sets of Vertical Launching System (VLS)
-MK41 components for Direct Commercial Sales (DCS) launcher to support BMD missions employing the Standard Missile 3 (SM-3)
-Two (2) ship sets Launch Control Units (LCU) MK 235 Mod 9 with Vertical Launching System (VLS) Global Positioning System (GPS) Integrator (VGI)
-VLS launcher components including twenty-four (24) MK 448 Mod 1 Motor Control Panel
-Four (4) Programmable Power Supplies MK179 Mod 0
-Twenty-four (24) Launch Sequencers MK 5 Mod 1
-Four (4) Fiber Optic Distribution Boxes (FODB)
-Twenty-four (24) Single Module Junction Boxes
-Two (2) ship sets Gun Weapon System MK 34
-Two (2) ship sets MK 20 Electro-Optical Sensor System (EOSS)
-Two (2) ship sets of Cooperative Engagement Capability (CEC)
-Two (2) ship sets Global Command and Control System-Maritime (GCCS-M)
-Two (2) ship sets AN/SPQ-9B Radar
-Two (2) ship sets Enhanced AEGIS Combat Systems Trainer (ACTS) with communication suite
-Two (2) ship sets technical documentation
So if Australia was going to build a couple more AEGIS capable ships (based on a modified Atago-class, as Japan is planning) for example, well there's a bit over A$2 Billion to be spent if we went down an identical path, and that's 'apart' from the actual construction cost of the ships themselves!!!